Simplify CI test matrix

Author: FMCorz

.github/workflows/ci.yml

@@ -30,32 +30,25 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php: ['7.4', '8.0', '8.1', '8.2', '8.3']
-        moodle-branch: ['MOODLE_401_STABLE', 'MOODLE_402_STABLE', 'MOODLE_403_STABLE', 'MOODLE_404_STABLE', 'MOODLE_405_STABLE']
+        php: ['8.1', '8.2', '8.3']
+        moodle-branch: ['MOODLE_401_STABLE', 'MOODLE_404_STABLE', 'MOODLE_405_STABLE']
         database: [pgsql]
+        include:
+          # PHP 7.4, solely on Moodle 4.1.
+          - moodle-branch: MOODLE_401_STABLE
+            database: pgsql
+            php: 7.4
+
+          # PHP 8.0, with Moodle 4.1.
+          - moodle-branch: MOODLE_401_STABLE
+            database: pgsql
+            php: 8.0
+
         exclude:
           - moodle-branch: MOODLE_401_STABLE
             php: 8.2
           - moodle-branch: MOODLE_401_STABLE
             php: 8.3
-          - moodle-branch: MOODLE_402_STABLE
-            php: 7.4
-          - moodle-branch: MOODLE_402_STABLE
-            php: 8.3
-          - moodle-branch: MOODLE_403_STABLE
-            php: 7.4
-          - moodle-branch: MOODLE_403_STABLE
-            php: 8.0
-          - moodle-branch: MOODLE_403_STABLE
-            php: 8.3
-          - moodle-branch: MOODLE_404_STABLE
-            php: 7.4
-          - moodle-branch: MOODLE_404_STABLE
-            php: 8.0
-          - moodle-branch: MOODLE_405_STABLE
-            php: 7.4
-          - moodle-branch: MOODLE_405_STABLE
-            php: 8.0
 
     steps:
       - name: Check out repository code