Deployment: Fix minor versioning issues

[Teufelchen1]

Hi 🦤,

this fixes some issues that prevented make to work.

1. The log level needs to be capital. Otherwise the logging initialization will fail.
2. Pinning the container os: Two weeks in a row, ubuntu:latest did not work for me. Today it started working again...anyway, we can pin to a LTS version.
3. pydantic 2.0 did a big rework and I think it is no longer compatible? I guessed this version and could only do limited testing :/ if other maintainers could check which version is running on their machines, that would be great!
4. PWD is the only absolute value in the compose file. Replacing it with a relative path to be in line with the rest. (This one gave me a headache)

[aabadie]

How about making the code compatible with pydantic and latest ubuntu versions? I fear that otherwise the current state will rot quite a bit