Separate multi-node integ tests to their own job (opensearch-project#458

)

Signed-off-by: Daniel Widdis <[email protected]>

.github/workflows/CI.yml

@@ -79,7 +79,22 @@ jobs:
       - name: Build and Run Tests
         run: |
           ./gradlew integTest yamlRestTest
-      - name: Multi Nodes Integration Testing
-        if: matrix.java == '21'
+  integMultiNodeTest:
+    needs: [spotless, javadoc]
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
+        java: [21]
+    name: Multi-Node Integ Test JDK${{ matrix.java }}, ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up JDK ${{ matrix.java }}
+        uses: actions/setup-java@v4
+        with:
+          java-version: ${{ matrix.java }}
+          distribution: temurin
+      - name: Build and Run Tests
         run: |
           ./gradlew integTest -PnumNodes=3