Add Rails7.2, 8.0 and Ruby 3.4 to CI matrix

Also updated actions/checkout to the latest v4.

Author: willnet

.github/workflows/CI.yml

@@ -13,27 +13,37 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        active_record:
-          - '6.0'
-          - '6.1'
-          - '7.0'
-          - '7.1'
-        ruby:
-          - '2.7'
-          - '3.0'
-          - '3.1'
-          - '3.2'
         include:
-          - active_record: '5.1'
-            ruby: '2.7'
-          - active_record: '5.2'
-            ruby: '2.7'
-          - active_record: '7.1'
-            ruby: '3.3'
+          - { active_record: '5.1', ruby: '2.7' }
+          - { active_record: '5.2', ruby: '2.7' }
+          - { active_record: '6.0', ruby: '2.7' }
+          - { active_record: '6.0', ruby: '3.0' }
+          - { active_record: '6.0', ruby: '3.1' }
+          - { active_record: '6.0', ruby: '3.2' }
+          - { active_record: '6.1', ruby: '2.7' }
+          - { active_record: '6.1', ruby: '3.0' }
+          - { active_record: '6.1', ruby: '3.1' }
+          - { active_record: '6.1', ruby: '3.2' }
+          - { active_record: '7.0', ruby: '2.7' }
+          - { active_record: '7.0', ruby: '3.0' }
+          - { active_record: '7.0', ruby: '3.1' }
+          - { active_record: '7.0', ruby: '3.2' }
+          - { active_record: '7.1', ruby: '2.7' }
+          - { active_record: '7.1', ruby: '3.0' }
+          - { active_record: '7.1', ruby: '3.1' }
+          - { active_record: '7.1', ruby: '3.2' }
+          - { active_record: '7.1', ruby: '3.3' }
+          - { active_record: '7.2', ruby: '3.1' }
+          - { active_record: '7.2', ruby: '3.2' }
+          - { active_record: '7.2', ruby: '3.3' }
+          - { active_record: '7.2', ruby: '3.4' }
+          - { active_record: '8.0', ruby: '3.2' }
+          - { active_record: '8.0', ruby: '3.3' }
+          - { active_record: '8.0', ruby: '3.4' }
     env:
       ACTIVERECORD: ${{ matrix.active_record }}
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Set up Ruby
       uses: ruby/setup-ruby@v1
       with: