Change minimum to PHP 8.1

Author: odan

.github/workflows/build.yml

@@ -19,7 +19,7 @@ jobs:
         uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ matrix.php-versions }}
-          extensions: xml, pcov, mbstring, pdo, pdo_mysql, intl, zip
+          extensions: mbstring, intl, zip
           coverage: none
 
       - name: Check PHP Version