Update ci.yml

Author: rennokki

.github/workflows/ci.yml

@@ -23,11 +23,14 @@ jobs:
           - '8.0'
           - '8.1'
         laravel:
+          - 8.*
           - 9.*
         prefer:
           - 'prefer-lowest'
           - 'prefer-stable'
         include:
+          - laravel: '8.*'
+            testbench: '6.*'
           - laravel: '9.*'
             testbench: '7.*'