[Ex CI] create centralized Azure CI dispatcher workflow

[danielsu-amd]

Creates an azure-ci-dispatcher Github Action which is intended to be the one-stop shop for Azure CI runs on PRs. This action is intended to completely replace the existing Azure CI triggers once verified to be fully functional. It allows for:

• A single check encompassing all Azure CI runs, allows only one 'required' check to be set
• Skipped Azure runs will not be shown in a PR's check list
• Much more flexibility on triggering Azure CI, since Github Actions have better integration with the rest of the website
  • ex. Can trigger Azure when drafts are set to 'ready for review'
  • ex. Can trigger Azure with a label (not implemented in here)

The action is 'smarter' and will skip CI runs that are already covered by an upstream dependency's run.

• ex. a PR touching rocPRIM and rocThrust will only trigger a rocPRIM run, which already will build rocThrust as part of its downstream jobs.

Once runs are started, the action will periodically query the Azure API for the jobs' statuses. Once all jobs are finished, the action will exit successfully if all jobs are successful, or will exit unsuccessfully if any jobs are unsuccessful.

Some test runs:

• PR touching all migrated libraries
  • https://github.com/danielsu-amd/rocm-libraries/actions/runs/15853626253/job/44693261537
• hipblas-common only
  • https://github.com/danielsu-amd/rocm-libraries/actions/runs/15853787609/job/44693804663
• rocrand, hiprand, hipcub
  • https://github.com/danielsu-amd/rocm-libraries/actions/runs/15854000821/job/44694517617

This currently does not have any functionality for include/exclude file patterns (these fields), any suggestions on how we could do that are welcome.