The latest tagged release (v0.1.3) does not pin any versions in its
Dockerfile and as such fails to build right now.

The `main` branch of rust-synapse-compress-state has already addressed
this and is buildable, but there's no tagged release yet.

Reported here: https://github.com/matrix-org/rust-synapse-compress-state/issues/134

This provides an additional security benefit. The password won't leak in
the process list anymore.

It will, additionally, be connected to the devture-postgres network, if
devture-postgres is enabled.