Use uv to install pip dependencies

[alastair]

Description
The idea here is to speed up the build process, both for developers and deployment process, and also during PR jobs - uv pip install is about 4x faster than pip install

This saves another 30 seconds on the github actions, bringing total run time down from ~4 minutes to ~3:30

Should we use uv?
the uv pip commands are 100% compatible with pip.
uv is developed by a commercial company, which might give us concern. However, we're also planning on using ruff for formatting and linting, by the same company, so I don't see an issue bringing in another tool by them