Add version tag comments for pinned GitHub Action SHAs in workflow files

[WilliamBerryiii]

Context

From PR review comment on #267: #267 (comment)

When GitHub Actions are pinned to a specific commit SHA, a version tag comment (e.g. # v8.0.1) should be added alongside the SHA for readability and auditability.

Details

In .github/workflows/application-matrix-builds.yml (and potentially other workflow files), pinned action references like:

uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c

should include a trailing version comment:

uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1

Acceptance Criteria

• Audit all workflow files under .github/workflows/ for pinned action SHAs missing version tag comments
• Add version tag comments to all pinned action references