install python tools for code formatting

.devcontainer/Dockerfile

@@ -212,5 +212,7 @@ RUN sudo chown --from=root:root citus:citus -R ~
 # sets default pg version
 RUN pgenv switch 16.1
 
+RUN --mount=type=bind,source=requirements.txt,target=requirements.txt pip install -r requirements.txt
+
 # make connecting to the coordinator easy
 ENV PGPORT=9700

.devcontainer/devcontainer.json

@@ -1,5 +1,5 @@
 {
-    "image": "ghcr.io/citusdata/citus-devcontainer:main",
+    "image": "ghcr.io/citusdata/citus-devcontainer:devcontainer-format-tools",
     "runArgs": [
         "--cap-add=SYS_PTRACE",
     ],