add Ruby 3.4 to the test matrix for real this time

Author: anmarchenko

.github/workflows/test.yml

@@ -14,6 +14,9 @@ jobs:
       fail-fast: false
       matrix:
         engine:
+        - name: ruby
+          version: '3.4'
+          alias: ruby-34
         - name: ruby
           version: '3.3'
           alias: ruby-33
@@ -32,6 +35,7 @@ jobs:
     container:
       image: ghcr.io/datadog/images-rb/engines/${{ matrix.engine.name }}:${{ matrix.engine.version }}
     outputs:
+      ruby-34-matrix: "${{ steps.set-matrix.outputs.ruby-34 }}"
       ruby-33-matrix: "${{ steps.set-matrix.outputs.ruby-33 }}"
       ruby-32-matrix: "${{ steps.set-matrix.outputs.ruby-32 }}"
       ruby-31-matrix: "${{ steps.set-matrix.outputs.ruby-31 }}"
@@ -55,6 +59,29 @@ jobs:
         path: 'Gemfile.lock
 
           '
+  test-ruby-34:
+    name: 'ruby-3.4: ${{ matrix.task }} (${{ matrix.group }})'
+    needs:
+    - compute_tasks
+    runs-on: ubuntu-22.04
+    strategy:
+      fail-fast: false
+      matrix:
+        include: "${{ fromJSON(needs.compute_tasks.outputs.ruby-34-matrix) }}"
+    container:
+      image: ghcr.io/datadog/images-rb/engines/ruby:3.4
+      env:
+        BUNDLE_GEMFILE: "${{ matrix.gemfile }}"
+    steps:
+    - uses: actions/checkout@v4
+    - name: Configure Git
+      run: git config --global --add safe.directory "$GITHUB_WORKSPACE"
+    - uses: actions/download-artifact@v4
+      with:
+        name: bundled-lock-${{ github.run_id }}-ruby-34
+    - run: bundle install && bundle exec rake compile_ext
+    - name: Test ${{ matrix.task }} with ${{ matrix.gemfile }}
+      run: bundle exec rake spec:${{ matrix.task }}
   test-ruby-33:
     name: 'ruby-3.3: ${{ matrix.task }} (${{ matrix.group }})'
     needs: