chore: Fix several style lints (#17488)

It's not comprehensive enough to start linting on `style` group, but
hey, it's a start.

Release Notes:

- N/A

crates/language_model/src/provider/open_ai.rs

@@ -55,7 +55,7 @@ pub struct State {
     _subscription: Subscription,
 }
 
-const OPENAI_API_KEY_VAR: &'static str = "OPENAI_API_KEY";
+const OPENAI_API_KEY_VAR: &str = "OPENAI_API_KEY";
 
 impl State {
     fn is_authenticated(&self) -> bool {