Disable flaky test_git_status_postprocessing test (#43293)

Release Notes:

- N/A

crates/project/src/project_tests.rs

@@ -8453,6 +8453,7 @@ async fn test_git_repository_status(cx: &mut gpui::TestAppContext) {
 }
 
 #[gpui::test]
+#[ignore]
 async fn test_git_status_postprocessing(cx: &mut gpui::TestAppContext) {
     init_test(cx);
     cx.executor().allow_parking();