Modernise and align API with FastAPI idiomatic patterns

[THEGOLDENPRO]

• Switched to UV for the docker image and added a lock file so code is more reproducible.
• Dropped all past Python versions to prioritize for Python 3.12+ support (the docker image also uses 3.12).
• Replaced unmaintained slowapi library with fastapi-limiter for rate limiting (this was a blocker while making the code more idiomatic).
• Removed GIT_REPO_x environment variables as it makes no sense to even use them.
• Updated to the latest dependencies (including fastapi).
• Brought in some new tooling (uv and ty) to improve maintainability.
• Allowed passing proxy headers to the API to help with rate limiting.
• Cleaned up and removed a bunch of my old python code (not everything has been refactored).
• Removed devgoldyutils and typing-extensions.
• Updated some README instructions.
• Added ty and ruff check workflows.

[THEGOLDENPRO]

I've done a lot of changes so I'll need to test run this for a while before I push it to docker hub. In theory nothing should have changed from the client facing side (all api wrappers and client should just work). I didn't touch any responses on purpose.

I'm new to using uv in docker and the fastapi-limiter library so please do let me know if anything there or anywhere else in fact is out of place.

[THEGOLDENPRO]

Should merge this soon.

[THEGOLDENPRO]

Okay merging this now, I'll do a github and docker release later.