chore: Prepare for Rust edition bump to 2024 (without autofix) (#27791)

Successor to #27779 - in this PR I've applied changes manually, without
futzing with if let lifetimes at all.

Release Notes:

- N/A

crates/language_model/src/rate_limiter.rs

@@ -52,7 +52,7 @@ impl RateLimiter {
     pub fn stream<'a, Fut, T>(
         &self,
         future: Fut,
-    ) -> impl 'a + Future<Output = Result<impl Stream<Item = T::Item>>>
+    ) -> impl 'a + Future<Output = Result<impl Stream<Item = T::Item> + use<Fut, T>>>
     where
         Fut: 'a + Future<Output = Result<T>>,
         T: Stream,