zed: Remove unnecessary clones (#29513)

`App::http_client` and `Client::http_client` both return an owned `Arc`
which it clones internally. This means we can remove unnecessary clones
when calling these methods.

Release Notes:

- N/A

crates/agent/src/buffer_codegen.rs

@@ -503,7 +503,7 @@ impl CodegenAlternative {
             }
         }
 
-        let http_client = cx.http_client().clone();
+        let http_client = cx.http_client();
         let telemetry = self.telemetry.clone();
         let language_name = {
             let multibuffer = self.buffer.read(cx);