chore(deps): update actions/checkout action to v4 (#167)

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

.github/workflows/composer-diff.yml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           # Required to make it possible to compare with PR base branch
           fetch-depth: 0

.github/workflows/php.yml

@@ -27,7 +27,7 @@ jobs:
           coverage: xdebug
           tools: php-cs-fixer, phpunit:${{ matrix.phpunit-versions }}
 
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - name: Validate composer.json and composer.lock
         run: composer validate