Update infection.yaml

Author: gplanchat

.github/workflows/infection.yaml

@@ -7,7 +7,7 @@ jobs:
             -   uses: actions/checkout@v2
             -   uses: shivammathur/setup-php@v2
                 with:
-                    php-version: '8.0'
+                    php-version: '8.1'
                     tools: composer:v2
                     coverage: pcov
             -   uses: actions/cache@v2
@@ -19,7 +19,7 @@ jobs:
             -   uses: php-actions/composer@v5
                 with:
                     args: --prefer-dist
-                    php_version: 8.0
+                    php_version: 8.1
 
             -   name: Infection
                 run: |