Add tests for workflows shipped with the creators package

[aalves08]

Summary

Fixes #12657

Occurred changes and/or fixed issues

• add script to do content match of creators workflows files
• update workflows for extensions tests to run this new check

Technical notes summary

Areas or cases that should be tested

Areas which could experience regressions

Screenshot/Video

Checklist

• The PR is linked to an issue and the linked issue has a Milestone, or no issue is needed
• The PR has a Milestone
• The PR template has been filled out
• The PR has been self reviewed
• The PR has a reviewer assigned
• The PR has automated tests or clear instructions for manual tests and the linked issue has appropriate QA labels, or tests are not needed
• The PR has reviewed with UX and tested in light and dark mode, or there are no UX changes

[cnotv]

I think it may be worth to try the CI on your fork on push, just to be sure.
Anyhow, if it works for you, I see no reason to block this.

LGTM

[jordojordo]

I've simplified this workflow configuration while maintaining all existing functionality. Here's what changed:

• Consolidated Workflows
  • Merged 3 separate workflows (master, release-2.9, release-2.8) into a single workflow using a matrix strategy
• Refactored check-creators-workflows-code.sh to:
  • Use HEREDOC for cleaner template management
  • Added explicit error messaging with ::error:: commands
  • Implemented proper diff-based comparison
• Added a dedicated aggregation job to maintain compatibility with existing Slack notifications