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/collab_ui/src/collab_panel/channel_modal.rs

@@ -309,7 +309,7 @@ impl PickerDelegate for ChannelModalDelegate {
                             let members = search_members.await?;
                             picker.update(&mut cx, |picker, cx| {
                                 picker.delegate.has_all_members =
-                                    query == "" && members.len() < 100;
+                                    query.is_empty() && members.len() < 100;
                                 picker.delegate.matching_member_indices =
                                     (0..members.len()).collect();
                                 picker.delegate.members = members;