[TASK] Migrate workflows to shared reusable workflows from .github

[CybotTM]

Summary

Migrates test-documentation.yml and apply-precommit.yml to use the shared
reusable workflows from TYPO3-Documentation/.github.

The backport.yml was already migrated. The tests.yml remains repo-specific
as it uses Build/Scripts/runTests.sh.

Changes

Workflow	Before	After
test-documentation.yml	15 lines inline (Docker)	Shared reusable-test-documentation.yml (8 lines)
apply-precommit.yml	60 lines inline	Shared reusable-apply-precommit.yml (12 lines)
backport.yml	Already shared	No change
tests.yml	Repo-specific	No change

Benefits

• Single point of maintenance — action version updates happen centrally
• Consistent behavior — all documentation repos render-test the same way
• Less boilerplate — ~70 lines reduced to ~20 lines across two workflows

Dependencies and merge order

• Depends on .github#2 (adds reusable-test-documentation.yml and reusable-apply-precommit.yml)

[linawolf]

Before we start changing other workflows that are currently working I really need to get the backport workflow to working again. and it currently does not work. can you fix the backport workflow in this repository first please?

[linawolf]

Let us try this out, we can always roll back

[typo3-docs-backport-bot]

Backport failed for 12.4, because it was unable to cherry-pick the commit(s).

Please cherry-pick the changes locally and resolve any conflicts.

git fetch origin 12.4
git worktree add -d .worktree/backport-792-to-12.4 origin/12.4
cd .worktree/backport-792-to-12.4
git switch --create backport-792-to-12.4
git cherry-pick -x 6a4b690b8be86d407be4fc7c21b9d69d91abb1ab

[typo3-docs-backport-bot]

Successfully created backport PR for 13.4:

• [Backport 13.4] [TASK] Migrate workflows to shared reusable workflows from .github #802