Support pyrefly as alternative lsp for python

[0x1997]

Pyrefly is faster than pyright and more mature than ty. https://pyrefly.org/blog/speed-and-memory-comparison/
Command to start the lsp server is pyrefly lsp

[MischaPanch]

I don't mind adding it (in the same fashion as ty, installing on the fly with uvx), but do you really need it? ty is fast and good enough for all practical purposes, right?

[0x1997]

ty is a great project but it's still young. Popular packages like polars still has major compatibility issues (astral-sh/ty#2278).
You can check the type conformance test results at https://htmlpreview.github.io/?https://github.com/python/typing/blob/main/conformance/results/results.html

[MischaPanch]

Feel free to issue a PR, should be completely analogous to ty support