add alpha1 qualifier to assemble command in benchmark workflow (opensearch-project#17481)

Signed-off-by: Rishabh Singh <[email protected]>
Signed-off-by: Vinay Krishna Pudyodu <[email protected]>

Author: rishabh6788

.github/workflows/benchmark-pull-request.yml

@@ -147,7 +147,7 @@ jobs:
           distribution: 'temurin'
       - name: Build and Assemble OpenSearch from PR
         run: |
-          ./gradlew :distribution:archives:linux-tar:assemble -Dbuild.snapshot=false
+          ./gradlew :distribution:archives:linux-tar:assemble -Dbuild.snapshot=false -Dbuild.version_qualifier=alpha1
       - name: Configure AWS credentials
         uses: aws-actions/configure-aws-credentials@v4
         with: