Fix a bunch of other low-hanging style lints (#36498)

- **Fix a bunch of low hanging style lints like unnecessary-return**
- **Fix single worktree violation**
- **And the rest**

Release Notes:

- N/A

crates/project/src/buffer_store.rs

@@ -234,7 +234,7 @@ impl RemoteBufferStore {
                 }
             }
         }
-        return Ok(None);
+        Ok(None)
     }
 
     pub fn incomplete_buffer_ids(&self) -> Vec<BufferId> {
@@ -1313,10 +1313,7 @@ impl BufferStore {
                     let new_path = file.path.clone();
 
                     buffer.file_updated(Arc::new(file), cx);
-                    if old_file
-                        .as_ref()
-                        .map_or(true, |old| *old.path() != new_path)
-                    {
+                    if old_file.as_ref().is_none_or(|old| *old.path() != new_path) {
                         Some(old_file)
                     } else {
                         None