Aktualisiere GHA Actions auf aktuelle Versionen (#78)

Batch-Commit via webfactory/bfg9000#16

Author: mpdude

.github/workflows/fix-cs-php.yml

@@ -16,7 +16,7 @@ jobs:
         if: github.actor != 'dependabot[bot]'
         steps:
             -   name: Checkout code
-                uses: actions/checkout@v4
+                uses: actions/checkout@v6
                 with:
                     ref: ${{ github.head_ref }}