treewide: Replace pip in favor of uv

[fischeti]

uv is a newer python package manager that is becoming more popular and it facilitates a couple of issues that we currently have. Essentially, it is a drop in replacement for pip and operates on the pyproject.toml description. But it has a couple of features and advantages that make it worth adapting:

• It provides a universal lock file uv.lock to lock the resolved python package version used in the project (and subprojects). This will also be familiar to people using bender (in fact both uv and bender are inspired by Cargo)
• It automatically installes the python version used in the project if it does not exist yet (i.e. the one that is pinned in .python-version)
• It automatically creates a virtual environment behind the scenes and makes sure that it is synced with the lock file
• It supports workspaces (resp. path dependencies as we know them from bender). This is not directly relevant for the snitch_cluster repository but for instance in picobello (see wip here), I can specify both floogen and snitch_cluster as dependencies and it will resolve the dependencies together, which is very convenient.
• workspaces can also be editable so when you update the bender dependencies, you don't need to regenerate the virtual environments.
• It supports adding specific indexes for python packages in pyproject.toml itself (looking at torch cpu-only version 👀).
• It is waaay faster than pip 🚀 and the way it is implemented now still supports pip based installations
• Last but not least, all the cool kidz are using it 😎

TODOs

• Check IIS internal CI (works on my internal gitlab fork)
• Decide where uv should be taken from in the IIS environment. It is a small binary that could be installed on the fly, but we could also install it system wide
• Adapt list-dependent-make-targets to specify python (inlined the action now with the uv environment)
• Check if caching in CI should be enabled/disabled/improved (cache directory is local to CI runner so shared amongst jobs and uv can link instead of copy since it is on the same file system)
• Merge nonfree PR, and revert nonfree commit

[colluca]

LGTM, let's wait on the remaining TODOs and then merge :)