project: Compare WorktreePaths by pairing, not by path sets (#62144)

# Objective

- Prevent changed main/folder associations from being skipped during
thread metadata updates.

## Solution

- Compare WorktreePaths as ordered main/folder pairs.
- Keep PathList equality order-insensitive.

## Testing

- cargo test -p project test_worktree_paths_equality_compares_pairings

## Self-Review Checklist:

- [x] I have reviewed my own diff for quality, security, and reliability
- [x] Unsafe blocks (if any) have justifying comments
- [x] The content adheres to Zed UI standards
- [x] Tests cover the new/changed behavior
- [x] Performance impact has been considered and is acceptable

---

Release Notes:

- N/A

crates/project/src/worktree_store.rs

@@ -50,7 +50,7 @@ pub struct WorktreePaths {
 
 impl PartialEq for WorktreePaths {
     fn eq(&self, other: &Self) -> bool {
-        self.paths == other.paths && self.main_paths == other.main_paths
+        self.ordered_pairs().eq(other.ordered_pairs())
     }
 }