Add deepclean to the Docker image.

images/docker/Dockerfile

@@ -4,6 +4,8 @@ RUN apk add --update-cache --no-cache \
         docker-compose \
         docker-py \
         py3-dotenv \
+        py3-pip \
     && \
+    python3 -m pip install --no-cache-dir --progress-bar=off deepclean && \
     rm -rf /root/.cache /tmp/* /var/tmp/*
 COPY --chown=root:root compose-health-check /usr/local/bin/