Fix unnecessary-mut-passed lint (#36490)

Release Notes:

- N/A

crates/search/src/buffer_search.rs

@@ -1340,7 +1340,7 @@ impl BufferSearchBar {
         if self.query(cx).is_empty()
             && let Some(new_query) = self
                 .search_history
-                .current(&mut self.search_history_cursor)
+                .current(&self.search_history_cursor)
                 .map(str::to_string)
         {
             drop(self.search(&new_query, Some(self.search_options), window, cx));

crates/search/src/project_search.rs

@@ -4111,7 +4111,7 @@ pub mod tests {
         });
         cx.run_until_parked();
         let project_search_view = pane
-            .read_with(&mut cx, |pane, _| {
+            .read_with(&cx, |pane, _| {
                 pane.active_item()
                     .and_then(|item| item.downcast::<ProjectSearchView>())
             })