update sandbox check to publish latest UnifiedQueryAPI jars to maven local. (opensearch-project#21569)

This is a temporary work-around to publish latest unified jars
built to integrate with analytics-engine to maven local - we are working off of
a feature branch of sql in the short term.  if the step fails, the build will continue
with jars from maven central. This will be removed once changes for
analytics-engine in sql are merged to mainline.

Signed-off-by: Marc Handalian <marc.handalian@gmail.com>

Author: mch2

.github/workflows/sandbox-check.yml

@@ -32,8 +32,18 @@ jobs:
         uses: dtolnay/rust-toolchain@stable
       - name: Install protobuf compiler
         run: sudo apt-get update && sudo apt-get install -y protobuf-compiler
+      - name: Check out SQL repo (mustang-ppl-integration)
+        uses: actions/checkout@v6
+        with:
+          repository: opensearch-project/sql
+          ref: feature/mustang-ppl-integration
+          path: sql
+      - name: Publish unified-query artifacts to maven local
+        working-directory: sql
+        continue-on-error: true
+        run: ./gradlew publishUnifiedQueryPublicationToMavenLocal
       - name: Run sandbox check
-        run: ./gradlew check -p sandbox -Dsandbox.enabled=true
+        run: ./gradlew check -p sandbox -Dsandbox.enabled=true -Drepos.mavenLocal=true -PrustDebug
       - name: Upload test results
         if: always()
         uses: actions/upload-artifact@v4