php: Utilize shivammathur/setup-php@v2

Author: nilmerg

.github/workflows/php.yml

@@ -69,7 +69,7 @@ jobs:
         uses: actions/checkout@v2
 
       - name: Setup PHP
-        uses: shivammathur/setup-php@v1
+        uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ matrix.php }}
           tools: phpunit:${{ matrix.phpunit-version || env.phpunit-version }}