fix: Combine branch and commit refresh into a single thread

Author: gadfly3173

src/Models/Watcher.cs

@@ -120,8 +120,11 @@ private void Tick(object sender)
                     Task.Run(_repo.RefreshSubmodules);
                 }
 
-                Task.Run(_repo.RefreshBranches);
-                Task.Run(_repo.RefreshCommits);
+                Task.Run(() =>
+                {
+                    _repo.RefreshBranches();
+                    _repo.RefreshCommits();
+                });
                 Task.Run(_repo.RefreshWorkingCopyChanges);
                 Task.Run(_repo.RefreshWorktrees);
             }