Adding 4.01 to CI.

Author: mchurchward

.github/workflows/ci.yml

@@ -9,7 +9,7 @@ jobs:
       matrix:
         include:
           - php: '8.0'
-            moodle-branch: 'master'
+            moodle-branch: 'MOODLE_401_STABLE'
             database: 'pgsql'
           - php: '8.0'
             moodle-branch: 'MOODLE_400_STABLE'