Automatic configuration reloading for ruff server (#10404)

## Summary

Fixes #10366.

`ruff server` now registers a file watcher on the client side using the
LSP protocol, and listen for events on configuration files. On such an
event, it reloads the configuration in the 'nearest' workspace to the
file that was changed.

## Test Plan

N/A

crates/ruff_server/src/server/api.rs

@@ -65,6 +65,9 @@ pub(super) fn notification<'a>(notif: server::Notification) -> Task<'a> {
         notification::DidChangeConfiguration::METHOD => {
             local_notification_task::<notification::DidChangeConfiguration>(notif)
         }
+        notification::DidChangeWatchedFiles::METHOD => {
+            local_notification_task::<notification::DidChangeWatchedFiles>(notif)
+        }
         notification::DidChangeWorkspace::METHOD => {
             local_notification_task::<notification::DidChangeWorkspace>(notif)
         }