Manually install unreleased version of docker-py

Brings in a fix for docker/docker-py#3240,
until docker-py is released upstream.

Ref jupyterhub#117

Dockerfile

@@ -4,6 +4,11 @@ RUN apk add --no-cache curl build-base python3 python3-dev py3-pip
 
 RUN python3 -m pip install --upgrade wheel setuptools
 
+# Manually install unreleased version of docker-py to bring in
+# fix for https://github.com/docker/docker-py/issues/3240
+# The hash is the 'main' branch of docker-py as of this writing (2024-03-25)
+RUN pip install --upgrade git+https://github.com/docker/docker-py@3d79ce8c603bd26e452e115c08aa4c670cc5ba54
+
 # https://stackoverflow.com/a/41651363/1695486
 RUN apk add --no-cache curl curl-dev
 COPY create_docker_image.sh /create_docker_image.sh