fix: add exclusion for Laravel 12 with PHP 8.1 in test matrix

Author: SRWieZ

.github/workflows/run-tests.yml

@@ -38,6 +38,8 @@ jobs:
         exclude:
           - laravel: 11.*
             php: 8.1
+          - laravel: 12.*
+            php: 8.1
 
     name: P${{ matrix.php }} - L${{ matrix.laravel }} - ${{ matrix.stability }} - ${{ matrix.os }}