Update Maven command to use flatten-poms profile

Author: alexheifetz

.github/workflows/deploy-snapshots.yml

@@ -26,4 +26,4 @@ jobs:
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }} 
 
-        run: mvn -DskipTests=true clean deploy
+        run: mvn -P flatten-poms -DskipTests=true clean deploy