chore: fix release workflow trigger for RubyGems publish

[fortissimo1997]

Summary

Fix the GitHub Actions workflow used for publishing gems to RubyGems.

• Adjust release.yml trigger:
  • Previously types: [published] (did not fire for release-please)
  • Now types: [released, published] so it runs on release-please events
• Commit message updated to chore: so release-please does not cut an
  unnecessary patch release.

Notes

• This change only affects CI/CD; no runtime code is modified.
• After merging, creating a GitHub Release (e.g. v0.9.0) should
  correctly trigger the publish job.

[coveralls]

coverage: 91.304%. remained the same
when pulling df21b45 on fix-release-workflow
into 69d9d16 on master.