Ensure local postgres docker container version matches the postgres version in the bitnami helm chart set up by the infra repo

[Greenheart]

This needs to be clearly documented, for example by specifying the right version of postgres in the README.

The docker run commands should use the same postgres version, which should be
postgres:16.4-bookworm to match bitnami.

Otherwise we might run into problems with differences in behaviour during development, testing and production