Make git change detection in PR presubmits more robust.

[igorpeshansky]

Description

Switch from jitterbit/get-changed-files to Ana06/get-changed-files, to fix the errors it produces on force-pushed PR branches:

Error: The head commit for this pull_request event is not ahead of the base commit. Please submit an issue on this action's GitHub repo.

This is apparently a known issue: jitterbit/get-changed-files#11.

Note: an alternative would have been to use continue-on-error: true…

Related issue

b/238471194

How has this been tested?

Force-pushed the branch, which ran the presubmit successfully.

Checklist:

• Unit tests
  • Unit tests do not apply.
  • Unit tests have been added/modified and passed for this PR.
• Integration tests
  • Integration tests do not apply.
  • Integration tests have been added/modified and passed for this PR.
• Documentation
  • This PR introduces no user visible changes.
  • This PR introduces user visible changes and the corresponding documentation change has been made.
• Minor version bump
  • This PR introduces no new features.
  • This PR introduces new features, and there is a separate PR to bump the minor version since the last release already.
  • This PR bumps the version.

[avilevy18]

Great find! After considering it be a bit more, I think we should move to
Ana06/[email protected]

[igorpeshansky]

Yeah, the latest version of Ana06/get-changed-files is v2.2.0, so we might as well switch to that.