chore(deps): pin dependencies (#66)

.github/workflows/php.yml

@@ -19,7 +19,7 @@ jobs:
 
     steps:
       - name: Setup PHP
-        uses: shivammathur/setup-php@v2
+        uses: shivammathur/setup-php@9e72090525849c5e82e596468b86eb55e9cc5401 # v2
         with:
           php-version: ${{ matrix.php-versions }}
           extensions: mbstring, intl, fileinfo
@@ -27,14 +27,14 @@ jobs:
           coverage: xdebug
           tools: php-cs-fixer, phpunit:${{ matrix.phpunit-versions }}
 
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
 
       - name: Validate composer.json and composer.lock
         run: composer validate --strict
 
       - name: Cache Composer packages
         id: composer-cache
-        uses: actions/cache@v4
+        uses: actions/cache@1bd1e32a3bdc45362d1e726936510720a7c30a57 # v4
         with:
           path: vendor
           key: ${{ runner.os }}-php-${{ matrix.php-versions }}-${{ hashFiles('**/composer.lock') }}