Fix replacement of matrix variables

Author: bram-pkg

.github/workflows/phpunit.yml

@@ -11,7 +11,7 @@ on:
 
 jobs:
   phpunit:
-    name: P${{ matrix.php }} - L${{ matrix.laravel }} - ${{ matrix.stability }} - ${{ matrix.os }}
+    name: "P${{ matrix.php }} - L${{ matrix.laravel }} - ${{ matrix.stability }} - ${{ matrix.os }}"
     runs-on: "${{ matrix.os }}"
     timeout-minutes: 5