ci: remove -amd64 suffix from GAIE deploy test image tag (#7848)

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.github/workflows/post-merge-ci.yml

@@ -438,7 +438,7 @@ jobs:
           extra_pytest_args: >-
             -m framework_with_gaie
             --frontend-image=${{ secrets.AZURE_ACR_HOSTNAME }}/ai-dynamo/dynamo:${{ github.sha }}-frontend
-            --image=${{ secrets.AZURE_ACR_HOSTNAME }}/ai-dynamo/dynamo:${{ github.sha }}-vllm-runtime-cuda12-amd64
+            --image=${{ secrets.AZURE_ACR_HOSTNAME }}/ai-dynamo/dynamo:${{ github.sha }}-vllm-runtime-cuda12
 
   deploy-status-check:
     runs-on: ubuntu-latest