Run static analysis tools with PHP 8.1

Author: sebastianbergmann

.github/workflows/ci.yml

@@ -22,7 +22,7 @@ jobs:
       - name: Install PHP
         uses: shivammathur/setup-php@v2
         with:
-          php-version: 8.0
+          php-version: 8.1
           extensions: :apcu, :imagick
           coverage: none
           tools: none
@@ -42,7 +42,7 @@ jobs:
       - name: Install PHP
         uses: shivammathur/setup-php@v2
         with:
-          php-version: 8.0
+          php-version: 8.1
           extensions: :apcu, :imagick
           coverage: none
           tools: none