worktree: Disable flaky tests (test_write_file, test_git_status_postprocessing) (#26710)

Comment out flaky tests:
- `worktree_tests::test_write_file`
- `worktree_tests::test_git_status_postprocessing`

Job links:
- windows fail:
https://github.com/zed-industries/zed/actions/runs/13841766606/job/38730766252
- macos fail:
https://github.com/zed-industries/zed/actions/runs/13841766606/job/38730764118

That
[commit](85384fb9c6)
was a non-op script change, but in the [prior
commit](00359271d1)
[windows/macos
pass](https://github.com/zed-industries/zed/actions/runs/13841135221).

Similar experience with `worktree_tests::test_write_file` on both macOS
windows too.

- See also: https://github.com/zed-industries/zed/pull/26684

Release Notes:

- N/A

crates/worktree/src/worktree_tests.rs

@@ -845,7 +845,9 @@ async fn test_update_gitignore(cx: &mut TestAppContext) {
     });
 }
 
-#[gpui::test]
+// TODO: Fix flaky test.
+// #[gpui::test]
+#[allow(unused)]
 async fn test_write_file(cx: &mut TestAppContext) {
     init_test(cx);
     cx.executor().allow_parking();
@@ -2740,7 +2742,9 @@ async fn test_git_repository_status(cx: &mut TestAppContext) {
     });
 }
 
-#[gpui::test]
+// TODO: Fix flaky test.
+// #[gpui::test]
+#[allow(unused)]
 async fn test_git_status_postprocessing(cx: &mut TestAppContext) {
     init_test(cx);
     cx.executor().allow_parking();