chore(deps): update github actions (#6)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/phpunit.yml

@@ -15,7 +15,7 @@ jobs:
 
     services:
       mysql:
-        image: mysql:8.4
+        image: mysql:9.5
         env:
           MYSQL_ROOT_PASSWORD: root
           MYSQL_DATABASE: wordpress_test
@@ -33,7 +33,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Setup PHP ${{ matrix.php-version }}
         uses: shivammathur/setup-php@v2
@@ -47,7 +47,7 @@ jobs:
         run: echo "dir=$(composer config cache-files-dir)" >> $GITHUB_OUTPUT
 
       - name: Cache Composer dependencies
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: ${{ steps.composer-cache.outputs.dir }}
           key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.lock') }}
@@ -57,7 +57,7 @@ jobs:
         run: composer install --prefer-dist --no-progress
 
       - name: Checkout WordPress develop
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           repository: WordPress/wordpress-develop
           path: wordpress-develop