[TASK] Migrate remaining repos to shared reusable workflows

Context

The TYPO3-Documentation org is centralizing GitHub Actions workflows into shared reusable workflows in this repository. Initial PRs covered 4 repos:

• TYPO3CMS-Reference-CoreApi (#6414 closed — backport was migrated directly on main instead)
• TYPO3CMS-Tutorial-Editors (#258 open — migrates backport + documentation to @main references)
• TYPO3CMS-Tutorial-GettingStarted (#792 ✅ merged 2026-03-23)
• render-guides (#1196 open, approved)

Status update (2026-07-04)

The backport migration has since happened in 5 of the 6 repos below — but via per-repo SHA pins instead of @main, and the pins have already drifted (most repos pin 161f3be, one commit behind current main = 46ed94f, missing the backport success/failure labels fix). This is exactly the per-repo maintenance burden ADR-003 (#6) proposes to eliminate.

• TYPO3CMS-Reference-TCA — backport ✅ (@46ed94f, current); still inline: test-documentation.yml, tests.yml, apply-precommit.yml
• TYPO3CMS-Reference-Typoscript — backport ✅ (@161f3be, stale pin); still inline: test-documentation.yml, tests.yml, apply-precommit.yml
• TYPO3CMS-Reference-ViewHelper — backport ✅ (@161f3be, stale pin); still inline: documentation.yml, tests.yml, apply-precommit.yml
• TYPO3CMS-Tutorial-SitePackage — backport ✅ (@161f3be, stale pin); still inline: documentation.yml, apply-precommit.yml (repo-specific auto-pr-sitepackage.yml stays)
• TYPO3CMS-Guide-FrontendLocalization — backport ✅ (@161f3be, stale pin); still inline: test-documentation.yml, apply-precommit.yml
• blog_example — still uses the broken m-kuhn/backport@30b6e83 on main — the original urgent motivation for this initiative, and the last repo where it is unfixed on main. Migration PR open: blog_example#188

Remaining work

1. blog_example: migrate backport.yml to the shared workflow (urgent — currently broken). PR open: blog_example#188.
2. Migrate the remaining inline test-documentation.yml / documentation.yml / tests.yml workflows in the five repos above.
3. Unify the reference style (@main vs SHA pin) once ADR-003 (#6) is decided; the June SHA-pin migrations have already produced drift.

The current workflow inventory is documented in this repo's README.

Migration pattern

For each repo, replace inline workflow files with shared workflow calls:

# Before (inline)
jobs:
  backport:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@...
      - uses: m-kuhn/backport@30b6e83  # BROKEN

# After (shared)
jobs:
  backport:
    uses: TYPO3-Documentation/.github/.github/workflows/reusable-backport.yml@main

Related work since this issue was filed

• Version-branch drift (workflow bumps only land on main, maintained branches never get them) was root-caused via FrontendLocalization#136 / #137; per-repo Dependabot target-branch PRs now cover the maintained version branches of 10 repos (12.4/13.4/14.3; blog_example 12.4/13.4 — it has no 14.3 branch).
• #15 adds reusable-node-command.yml (first Node.js reusable; consumer: render-guides theme-js-tests).
• #16 adds a CI gate to this repository (actionlint, yamllint, zizmor, conformance) so @main consumers can rely on merges here being validated.

Start with the workflow inventory in the repository README and compare the listed repositories' inline workflow files: test-documentation.yml, documentation.yml, tests.yml, apply-precommit.yml, and blog_example's backport.yml. Review the open blog_example#188 migration and the reusable workflow files in this repository. Done means the remaining workflows use the shared calls, while the repo-specific auto-pr-sitepackage.yml remains in place.