Remove the last setup.py packaging path

Author: anth-volk

gcp/README.md

@@ -3,7 +3,7 @@
 The deployment actions build Docker images and deploy them to Google App Engine. The docker images themselves are based off a starter image (to save each API docker image having to spend 5 minutes installing the same dependencies). The starter image is the `Dockerfile` in this directory.
 
 To update the starter image:
-* `python setup.py sdist` to build the python package
+* `uv build` to build the python package
 * `twine upload dist/*` to upload the package to pypi as `policyengine-household-api`
 * `cd gcp`
 * `docker build .`