Simplify healthcheck in CI

Author: leplatrem

.github/workflows/build-publish.yaml

@@ -102,7 +102,8 @@ jobs:
 
       - name: Check that container is running
         run: |
-          docker exec ${{ env.TEST_CONTAINER_NAME }} bin/healthcheck.py
+          docker exec ${{ env.TEST_CONTAINER_NAME }} curl --retry 10 --retry-delay 1 --retry-connrefused http://0.0.0.0:8000/__heartbeat__
+
 
       - name: Spin down container
         run: |