[bazel] Bump default bazel version to 9.1.1 and bump CI workflow version

[shameekganguly]

🎉 New feature

Summary

• Bump bazel version to 9.1.1. Some deps need to be updated.
• Updates the bazel.yaml workflow version to 7.7.0, which brings improved caching (contributes to Enable caching for bazel CI gazebo-tooling/release-tools#1518)

Backport Policy

• This is safe to backport to the following versions:
  • Jetty
  • Ionic
  • Harmonic
  • Fortress
• This should not be backported
• I am not sure
• Other (fill in yourself)

Test it

bazel build ...

Checklist

• Signed all commits for DCO
• Added a screen capture or video to the PR description that demonstrates the feature
• Added tests
• Added example and/or tutorial
• Updated documentation (as needed)
• Updated migration guide (as needed)
• Consider updating Python bindings (if the library has them)
• codecheck passed (See contributing)
• All tests passed (See test coverage)
• Updated Bazel files (if adding new files). Created an issue otherwise.
• While waiting for a review on your PR, please help review another open pull request to support the maintainers
• Was GenAI used to generate this PR? If so, make sure to add "Generated-by" to your commits. (See this policy for more info.)

Generated-by: Gemini 3.5 Flash

Note to maintainers: Remember to use Squash-Merge and edit the commit message to match the pull request summary while retaining Signed-off-by and Generated-by messages.

Backports: If this is a backport, please use Rebase and Merge instead.

[shameekganguly]

@Mergifyio backport gz-physics9

[mergify]

backport gz-physics9

✅ Backports have been created

Details

• #1023 [bazel] Bump default bazel version to 9.1.1 and bump CI workflow version (backport #1022) has been created for branch gz-physics9