chore(build): update gapic-generator version to 1.37.1 and regenerate client libraries

[hebaalazzeh]

Summary

Updates the gapic-generator tool version to 1.37.1 in librarian.yaml and regenerates all Python client libraries across the monorepo.

Scope of Changes

• librarian.yaml: Verified gapic-generator tool version is set to 1.37.1 under tools.pip.
• Generated Client Libraries: Ran librarian generate --all to update all Python client libraries with the updated configuration.

Context & Approvals

Following the library generation workflow update (PR #17892 and googleapis/librarian PR #7019), generation now relies exclusively on the repository-level librarian.yaml.

[gemini-code-assist]

Code Review

This pull request performs a significant cleanup of the gapic-generator package, removing numerous service documentation and configuration files. I have reviewed the changes and identified an issue in the .python-version file, where a non-standard identifier is included that may cause environment setup errors for other developers.

[gemini-code-assist]

The .python-version file contains py314 on the second line. Standard .python-version files should only contain valid, globally resolvable Python version strings (like 3.14.0). Including a local virtualenv name or non-standard identifier like py314 will cause pyenv to raise errors (e.g., pyenv: version 'py314' is not installed) for other developers who do not have this specific virtualenv configured locally. It is recommended to remove this line.

3.14.0