chore: remove dead version check conditional

packages/gapic-generator/gapic/templates/%namespace/%name_%version/%sub/services/%service/_client_macros.j2

@@ -174,11 +174,6 @@
             {% endif %}
         )
         {% if method.lro %}
-        {% if service.version %}
-        lro_metadata = None
-        if HAS_GOOGLE_API_CORE_VERSION_HEADER:  # pragma: NO COVER
-            lro_metadata = [version_header.to_api_version_header("{{ service.version }}")]
-        {% endif %}
 
         # Wrap the response in an operation future.
         response = {{ method.client_output.ident.module_alias or method.client_output.ident.module }}.from_gapic(
@@ -187,7 +182,7 @@
             {{ method.lro.response_type.ident }},
             metadata_type={{ method.lro.metadata_type.ident }},
             {% if service.version %}
-            grpc_metadata=lro_metadata,
+            grpc_metadata=[version_header.to_api_version_header("{{ service.version }}")],
             {% endif %}
         )
         {% elif method.paged_result_field %}

packages/gapic-generator/gapic/templates/%namespace/%name_%version/%sub/services/%service/_shared_macros.j2

@@ -35,20 +35,8 @@
 {% endmacro %}
 
 {% macro add_google_api_core_version_header_import(service_version) %}
-{#
-The `version_header` module was added to `google-api-core`
-in version 2.19.0.
-https://github.com/googleapis/python-api-core/releases/tag/v2.19.0
-The `try/except` below can be removed once the minimum version of
-`google-api-core` is 2.19.0 or newer.
-#}
 {% if service_version %}
-try:
-    from google.api_core import version_header
-    HAS_GOOGLE_API_CORE_VERSION_HEADER = True  # pragma: NO COVER
-{# NOTE: `pragma: NO COVER` is needed since the coverage for presubmits isn't combined. #}
-except ImportError:  # pragma: NO COVER
-    HAS_GOOGLE_API_CORE_VERSION_HEADER = False
+from google.api_core import version_header
 {% endif %}{# service_version #}
 {% endmacro %}
 
@@ -98,10 +86,9 @@ except ImportError:  # pragma: NO COVER
     `add_google_api_core_version_header_import` to add the necessary import statements.
 #}
     {% if service_version %}
-        if HAS_GOOGLE_API_CORE_VERSION_HEADER:  # pragma: NO COVER
-            metadata = tuple(metadata) + (
-                version_header.to_api_version_header("{{ service_version }}"),
-            )
+        metadata = tuple(metadata) + (
+            version_header.to_api_version_header("{{ service_version }}"),
+        )
     {% endif %}{# service_version #}
 {% endmacro %}
 

packages/gapic-generator/gapic/templates/%namespace/%name_%version/%sub/services/%service/async_client.py.j2

@@ -430,11 +430,6 @@ class {{ service.async_client_name }}:
             {% endif %}
         )
         {% if method.lro %}
-        {% if service.version %}
-        lro_metadata = None
-        if HAS_GOOGLE_API_CORE_VERSION_HEADER:  # pragma: NO COVER
-            lro_metadata = [version_header.to_api_version_header("{{ service.version }}")]
-        {% endif %}
 
         # Wrap the response in an operation future.
         response = {{ method.client_output_async.ident.module_alias or method.client_output_async.ident.module }}.from_gapic(
@@ -443,7 +438,7 @@ class {{ service.async_client_name }}:
             {{ method.lro.response_type.ident }},
             metadata_type={{ method.lro.metadata_type.ident }},
             {% if service.version %}
-            grpc_metadata=lro_metadata,
+            grpc_metadata=[version_header.to_api_version_header("{{ service.version }}")],
             {% endif %}
         )
         {% elif method.paged_result_field %}

packages/gapic-generator/gapic/templates/tests/unit/gapic/%name_%version/%sub/_test_mixins.py.j2

@@ -1,11 +1,10 @@
 {% macro assert_api_version_header(service_version) -%}
 {% if service_version %}
 
-    if HAS_GOOGLE_API_CORE_VERSION_HEADER:  # pragma: NO COVER
-        assert (
-            version_header.API_VERSION_METADATA_KEY,
-            "{{ service_version }}",
-        ) in kw["metadata"]
+    assert (
+        version_header.API_VERSION_METADATA_KEY,
+        "{{ service_version }}",
+    ) in kw["metadata"]
 {%- endif -%}
 {% endmacro -%}
 {% if api.has_operations_mixin and ('grpc' in opts.transport or 'grpc_asyncio' in opts.transport) %}

packages/gapic-generator/gapic/templates/tests/unit/gapic/%name_%version/%sub/test_%service.py.j2

@@ -206,41 +206,35 @@ async def test_{{ method_name }}_api_version_header_async(transport_name="grpc")
 def test_{{ method_name }}_api_version_header(transport_name):
     client = {{ service.client_name }}(credentials=ga_credentials.AnonymousCredentials(), transport=transport_name)
 {% endif %}
-    # TODO: Make this test unconditional once the minimum supported version of
-    # google-api-core becomes 2.19.0 or higher.
-    api_core_major, api_core_minor = [int(part) for part in api_core_version.__version__.split(".")[0:2]]
-    if api_core_major > 2 or (api_core_major == 2 and api_core_minor >= 19):
-        # Mock the actual call within the gRPC stub, and fake the request.
-        with mock.patch.object(
-                type(client.transport.{{ method.transport_safe_name|snake_case }}),
-                '__call__'
-            ) as call:
-                call.return_value = {{ method.output.ident }}()
-            {% set response_prefix = "response = " if method.lro else "" %}
-            {% if mode == "async" %}
-                {{ response_prefix }}await client.{{ method_name }}()
-            {% else %}
-                {{ response_prefix }}client.{{ method_name }}()
-            {% endif %}
-
-        # Establish that the api version header was sent.
-        _, _, kw = call.mock_calls[0]
-        assert (
-            version_header.API_VERSION_METADATA_KEY,
-            "{{ service.version }}",
-        ) in kw['metadata']
-        {% if method.lro %}
-        assert (
-            version_header.API_VERSION_METADATA_KEY,
-            "{{ service.version }}",
-        ) in response._refresh.keywords["metadata"]
-        assert (
-            version_header.API_VERSION_METADATA_KEY,
-            "{{ service.version }}",
-        ) in response._cancel.keywords["metadata"]
+    # Mock the actual call within the gRPC stub, and fake the request.
+    with mock.patch.object(
+            type(client.transport.{{ method.transport_safe_name|snake_case }}),
+            '__call__'
+        ) as call:
+            call.return_value = {{ method.output.ident }}()
+        {% set response_prefix = "response = " if method.lro else "" %}
+        {% if mode == "async" %}
+            {{ response_prefix }}await client.{{ method_name }}()
+        {% else %}
+            {{ response_prefix }}client.{{ method_name }}()
         {% endif %}
-    else:
-        pytest.skip("google-api-core>=2.19.0 is required for `google.api_core.version_header`")
+
+    # Establish that the api version header was sent.
+    _, _, kw = call.mock_calls[0]
+    assert (
+        version_header.API_VERSION_METADATA_KEY,
+        "{{ service.version }}",
+    ) in kw['metadata']
+    {% if method.lro %}
+    assert (
+        version_header.API_VERSION_METADATA_KEY,
+        "{{ service.version }}",
+    ) in response._refresh.keywords["metadata"]
+    assert (
+        version_header.API_VERSION_METADATA_KEY,
+        "{{ service.version }}",
+    ) in response._cancel.keywords["metadata"]
+    {% endif %}
 {% endfor %}{# mode #}
 {% endwith %}
 {% endfor %}

packages/gapic-generator/gapic/templates/tests/unit/gapic/%name_%version/%sub/test_macros.j2

@@ -743,10 +743,9 @@ def test_{{ method_name }}_pager(transport_name: str = "grpc"):
         )
         {% endif %}
         {% if service.version %}
-        if HAS_GOOGLE_API_CORE_VERSION_HEADER:
-            expected_metadata = tuple(expected_metadata) + (
-                version_header.to_api_version_header("{{ service.version }}"),
-            )
+        expected_metadata = tuple(expected_metadata) + (
+            version_header.to_api_version_header("{{ service.version }}"),
+        )
         {% endif %}
         pager = client.{{ method_name }}(request={}, retry=retry, timeout=timeout)