Update ruff-lsp to ruff of Python

[ccqpein]

Try to update ruff-lsp to ruff

related issue: #4451

[jcs090218]

Should we rename the file lsp-ruff-lsp.el to lsp-ruff.el? 🤔

[ccqpein]

@jcs090218 I am ok with that. it makes sense with this PR

[jcs090218]

Can you update these following links and description?

• https://github.com/emacs-lsp/lsp-mode/blob/master/clients/lsp-ruff-lsp.el#L1
• https://github.com/emacs-lsp/lsp-mode/blob/master/clients/lsp-ruff-lsp.el#L23
• https://github.com/emacs-lsp/lsp-mode/blob/master/clients/lsp-ruff-lsp.el#L32
• https://github.com/emacs-lsp/lsp-mode/blob/master/mkdocs.yml#L141

We also need to rename all the variables' prefix from lsp-ruff-lsp to lsp-ruff.

[ccqpein]

@jcs090218 Just did. Hopefully I change all of them 😄

[jcs090218]

Can you update the CHANGELOG.org as well? Thank you! :D

[ccqpein]

@jcs090218 Just did.

[jcs090218]

And this, https://github.com/emacs-lsp/lsp-mode/blob/master/lsp-mode.el#L189. Almost forgot about it. 😅

[ccqpein]

@jcs090218 That's ok, you forget much less than I did 😂

[jcs090218]

LGTM! Thank you for your hard work! :D