Add support for Ruff linter pylsp plugin

[sh-shahrokhi]

Elevator Pitch

Adding support for Ruff linter will be great. It already has a pylsp plugin.

Motivation

It is a very fast linter written in Rust, with sane defaults. It can be used instead of many linters, like flake, pycodestyles, isort, pydocstyle, etc. and provides their functionality and more. Currently it does not work even if explicitly added to settings.json.

Design Ideas

It could be selectable in settings, in pylsp.configurationSources, like the current flake and pycodestyles options.

[krassowski]

You can install the plugin and it should just work, there is no modification needed. The only thing we could improve is including the configuration for that plugin in our schema.

[lauragalera]

Long time but I'd like to use ruff linter in our JupyterLab but it only detects pycodestyle. I installed python-lsp-ruff 2.2.2 and ruff 0.11.13. Despite adding this on the advanced settings > user preferences JSON

{
  "language_servers": {
    "pylsp": {
      "serverSettings": {
        "pylsp.plugins.pydocstyle.enabled": false,
        "pylsp.plugins.pyflakes.enabled": false,
        "pylsp.plugins.flake8.enabled": false,
        "pylsp.plugins.mccabe.enabled": false,
        "pylsp.plugins.ruff.enabled": true
      }
    }
  }
}

it doesn't show the ruff checks. Anything am I missing?