[CI] How about introducing `uv`?

[Seunghui98]

What

• Let's introduce uv for CI.
• What is uv? document
  • An extremely fast Python package and project manager, written in Rust.
  • Migrate to uv without changing your existing workflows — and experience a 10-100x speedup — with the uv pip interface.

Why

• pip with uv is performed at a faster rate, so faster execution of CI (such as check pr) is expected.

[mhs4670go]

To do this job, we would update our existing ccex tool. I guess it would be better to introduce a --installer option that allows users to choose between uv and pip via an option

Plan Summary

1. Add an --installer Option

Allow users to explicitly choose the installation backend.

./ccex install --installer pip    # default
./ccex install --installer uv

2. Graceful Fallback

If uv is selected but not installed on the system, fallback to pip automatically or prompt the user.

[INFO] 'uv' is not installed on this system.
[INFO] Falling back to 'pip' for installation.

Alternatively, exit with a helpful message:

[ERROR] 'uv' is not installed. Please install it or use --installer pip.

[miusic]

FYI,
I breifly tested how fast uv is, but it was not that effective than I expected
(ref: #55 (comment))

[Seunghui98]

@miusic

Oh, well, at least we can save about 30 seconds(?). 🤔