Fix publish pytest image bug (#5084)

Signed-off-by: Nquicksilver <zhifeng.zhang@zilliz.com>

.github/workflows/publish-test-images.yaml

@@ -46,6 +46,7 @@ jobs:
         if: success() && github.event_name == 'push' && github.repository == 'milvus-io/milvus'
         continue-on-error: true
         shell: bash
+        working-directory: tests/docker
         run: |
           docker login -u ${{ secrets.DOCKERHUB_USER }} \
                        -p ${{ secrets.DOCKERHUB_TOKEN }}