ci: patch laravel version

Author: nerg4l

.github/workflows/test.yml

@@ -16,7 +16,7 @@ jobs:
       fail-fast: false
       matrix:
         php: [ 7.3, 7.4 ]
-        laravel: [ '^6.10', '^7.0', '^7.8' ]
+        laravel: [ '^6.10', '^7.0', '^8.0' ]
         dependency-version: [prefer-lowest, prefer-stable]
 
     name: PHP ${{ matrix.php }} - Laravel ${{ matrix.laravel }}