CI: the arcadedb-jvm release tests 10 of 16 platform x Python legs (3.12 and 3.13 untested off Linux x86-64) #268

The arcadedb-jvm wheels are published after a test run that covers 10 of the 16 platform x Python combinations: scripts/select_matrix.py gives jvm the same legs on every event (all four Pythons on linux/amd64, only 3.11 and 3.14 on linux/arm64, darwin/arm64 and windows/amd64). Python 3.12 and 3.13 on macOS, Windows and Linux arm64 are never tested before a release, although the wheel claims them (classifiers, requires-python = ">=3.11,<3.15"). The native build already runs all 16 for a release (test-native.yml, release: true).

A second detail: release-jvm.yml calls test-jvm.yml as a reusable workflow, where github.event_name is the caller's event (the tag push), so the selector cannot tell a release from a push to main today.

Proposal: the 10 legs stay for pull requests, pushes to main and the nightly schedule (the organisation shares one runner cap with ArcadeData/arcadedb); a release and a manual dispatch run all 16, which adds 6 legs once per release. The release passes an explicit release: true input, as test-native.yml does.