ci: build matrix

Author: toshimaru

.github/workflows/ci.yml

@@ -56,6 +56,13 @@ jobs:
   doc-build-others:
     runs-on: ubuntu-latest
     name: Rails Doc Build (older versions)
+    strategy:
+      matrix:
+        include:
+          - ruby-version: 2.7
+            build-rails-versions: "5.2,6.0,6.1"
+          - ruby-version: 3.3
+            build-rails-versions: "7.0,7.1,7.2,8.0"
     steps:
       - uses: actions/checkout@v4
         with:
@@ -68,7 +75,7 @@ jobs:
           done
       - uses: ruby/setup-ruby@v1
         with:
-          ruby-version: 2.7
+          ruby-version: ${{ matrix.ruby-version }}
           bundler-cache: true
       - name: Doc Build
-        run: rake 'build_multi[v5.2,v6.0,v6.1]'
+        run: rake 'build_multi[${{ matrix.build-rails-versions }}]'