CI: Run 9.0 tests on PHP 8

Author: Naktibalda

.github/workflows/build.yml

@@ -8,7 +8,7 @@ jobs:
 
     strategy:
       matrix:
-        php: [7.3, 7.4]
+        php: [7.3, 7.4, 8.0]
 
     env:
       CODECEPTION_VERSION: '4.1.x-dev'
@@ -36,4 +36,4 @@ jobs:
         run: |
           php ./codecept run -c vendor/codeception/module-asserts/
           php ./codecept run unit -g core
-          php ./codecept run cli
+          php ./codecept run cli