Update GitHub Actions for Node 24 compatibility

Author: tzi

.github/workflows/tests.yml

@@ -22,7 +22,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
 
       - name: Setup PHP
         uses: shivammathur/setup-php@v2
@@ -35,7 +35,7 @@ jobs:
         run: composer validate --strict
 
       - name: Cache Composer dependencies
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: ~/.composer/cache/files
           key: composer-${{ runner.os }}-php-${{ matrix.php-version }}-${{ hashFiles('composer.json') }}