Bump actions/cache from 1 to 4

Bumps [actions/cache](https://github.com/actions/cache) from 1 to 4.
- [Release notes](https://github.com/actions/cache/releases)
- [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md)
- [Commits](actions/cache@v1...v4)

---
updated-dependencies:
- dependency-name: actions/cache
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/ci.yml

@@ -32,7 +32,7 @@ jobs:
       run: unzip redaxo_main.zip -d .
 
     - name: phpdoc cache
-      uses: actions/cache@v1
+      uses: actions/cache@v4
       with:
         path: .phpdoc
         key: branch-${{ github.ref }}