Update Quay login credentials in workflow

Use user workload image generated triggered from MR

Author: shruthis4

.github/workflows/execute-kfp-localrunners.yml

@@ -142,8 +142,8 @@ jobs:
         uses: docker/login-action@v3
         with:
          registry: ${{ env.QUAY_REGISTRY }}
-         username: ${{ secrets.QUAY_USERNAME }}
-         password: ${{ secrets.QUAY_PASSWORD }}
+         username: ${{ secrets.QUAY_USER_WORKLOAD_USERNAME }}
+         password: ${{ secrets.QUAY_USER_WORKLOAD_PASSWORD }}
 
       - name: Run local pipeline
         timeout-minutes: 15