[CI] Add ruff check

[trdthg]

resolve part of #525

Description

Currently, this PR includes the following content

• Auto fix by ruff: Most of it is about imports

  • Run ruff check --fix
  • Run ruff check . --fix --unsafe-fixes

• Manually fix

  • Contains the following content
    • fix imports.
      • Add missing imports, remove the unnecessary ones
      • Replace import * with specific content
    • unused variables: I didn't delete them, but replaced them with _xxx
    • lambda function: Replace with local def
    • == -> is
  • Fix cases that “ruff --check” can't handle

• Add CI, currently only running the ruff check command, I would like to separate ruff format --check to the next PR

  • [CI] Add ruff check and format

[jordancarlin]

Before adding this to CI it should probably be added to the documentation. Otherwise many people contributing will not be aware of it and will not format their code properly which will cause CI to fail. It might also make sense to have an easy way for people who don't already have it installed to run ruff locally, maybe using pre-commit.

[UmerShahidengr]

This is a large PR, changing plugins, riscv-isac source code, adding new things in the installation guide, updating CI. All of these things have to be documented first, otherwise we will not be able to achieve good code formatting and CI will keep failing.

[trdthg]

maybe using pre-commit; All of these things have to be documented first

Agree, I'm working on that, maybe added to CONTRIBUTION.md

At the same time, I noticed that because many places in the code use eval(), some import * and even some unused local variables still need to be retained, I am also checking this part.

This PR(include ci) does not perform any formatting(may be a few small places that I modified casually); the modifications are just to resolve lint errors or warnings.

[trdthg]

More commits here and I've allready test it with all cgfs for RV64

you can check current CI result at my fork repo https://github.com/trdthg/riscv-arch-test/actions

• Keep using some import * and variables in ctg and isca to support `…
  • these import * should be preserved to fit eval() call
• [CI] Add ruff-pre-commit hook
  • add pre-commit-hook and some document

[trdthg]

I will break this PR into some smaller parts