ci(docker): use correct tag for smoke test

.github/workflows/build_and_push_docker_images.yaml

@@ -182,7 +182,7 @@ jobs:
         timeout-minutes: 1
         run: |
           for tag in $(cat .emqx_docker_image_tags); do
-            CID=$(docker run -d -P $_EMQX_DOCKER_IMAGE_TAG)
+            CID=$(docker run -d -P $tag)
             HTTP_PORT=$(docker inspect --format='{{(index (index .NetworkSettings.Ports "18083/tcp") 0).HostPort}}' $CID)
             ./scripts/test/emqx-smoke-test.sh localhost $HTTP_PORT
             docker rm -f $CID