Automate weekly LICENSE Change Date updates #38014

Task Description

Automate weekly updates to the root LICENSE Change Date using a GitHub Actions scheduled workflow. Preserve the existing wording (Change Date: Four years from Month DD, YYYY) and replace only the date with the current UTC date.

Status: IN PROGRESS

Implementation

• Reuse .github/actions/update-license-date.sh with UTC and English date formatting.
• Run every Saturday at 23:00 UTC (0 23 * * 6); support manual dispatch.
• Try a normal commit/push to the repository default branch without force-pushing or bypassing branch protection.
• If direct push fails, create or update one PR using the organization machine-user credentials (CI_MACHINE_TOKEN, CI_MACHINE_USER, defaulting to dotcmsmachineuser).
• Include offline tests for date-only updates, idempotent reruns, direct-push behavior, PR fallback wiring, and missing credentials.

Acceptance Criteria

• Workflow runs Saturday at 23:00 UTC and can be manually dispatched.
• Date uses UTC and Month DD, YYYY, preserving Four years from and all other license text.
• No commit or PR is created when the date is already current.
• Direct push respects branch protection; rejected pushes fall back to a machine-user PR.
• Repeated fallback runs reuse a stable PR branch rather than creating duplicate PRs.
• Missing machine credentials produce a clear error when PR fallback is needed.
• Offline workflow tests and actionlint pass.

Operational Requirements

The repository must have access to the organization secrets CI_MACHINE_TOKEN and CI_MACHINE_USER. The machine-user token must be able to push the automation branch and create pull requests.