ci: remove php 8.1 from test matrix because composer requires 8.2

Author: thelfensdrfer

.github/workflows/tests.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-20.04
     strategy:
       matrix:
-        php-versions: ['8.1', '8.2', '8.3', '8.4']
+        php-versions: ['8.2', '8.3', '8.4']
 
     name: PHPUnit ${{ matrix.php-versions }}
     steps: