Run Java 11 tests on Gradle 8.14

Author: Goooler

.github/workflows/ci.yml

@@ -65,8 +65,7 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v4
-      - name: Install JDK ${{ matrix.distribution }} ${{ matrix.java_version }}
-        uses: actions/setup-java@v4
+      - uses: actions/setup-java@v4
         with:
           distribution: "temurin"
           java-version: ${{ matrix.jre }}
@@ -110,3 +109,37 @@ jobs:
           check_name: JUnit ${{ matrix.kind }} ${{ matrix.jre }} ${{ matrix.os }}
           report_paths: '*/build/test-results/*/TEST-*.xml'
           check_retries: true
+
+  # Gradle 9 requires Java 17 or higher, we use Gradle 8.14 (instead of gradlew) to build on Java 11.
+  build-on-java-11:
+    needs: sanityCheck
+    strategy:
+      fail-fast: false
+      matrix:
+        kind: [maven, gradle]
+        jre: [11]
+        os: [ubuntu-latest]
+    runs-on: ${{ matrix.os }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - uses: actions/setup-java@v4
+        with:
+          distribution: "temurin"
+          java-version: ${{ matrix.jre }}
+      - uses: gradle/actions/setup-gradle@v4
+        with:
+          gradle-version: 8.14.2
+      - name: build (maven-only)
+        if: matrix.kind == 'maven'
+        run: gradle :plugin-maven:build -x spotlessCheck
+      - name: build (everything-but-maven)
+        if: matrix.kind == 'gradle'
+        run: gradle build -x spotlessCheck -PSPOTLESS_EXCLUDE_MAVEN=true
+      - name: junit result
+        uses: mikepenz/action-junit-report@v5
+        if: always() # always run even if the previous step fails
+        with:
+          check_name: JUnit ${{ matrix.kind }} ${{ matrix.jre }} ${{ matrix.os }}
+          report_paths: '*/build/test-results/*/TEST-*.xml'
+          check_retries: true