sum_tree: Replace rayon with futures (#41586)

Release Notes:

- N/A *or* Added/Fixed/Improved ...

Co-authored by: Kate <kate@zed.dev>

crates/project/src/project_tests.rs

@@ -1461,21 +1461,21 @@ async fn test_reporting_fs_changes_to_language_servers(cx: &mut gpui::TestAppCon
     .unwrap();
     fs.save(
         path!("/the-root/Cargo.lock").as_ref(),
-        &"".into(),
+        &Rope::default(),
         Default::default(),
     )
     .await
     .unwrap();
     fs.save(
         path!("/the-stdlib/LICENSE").as_ref(),
-        &"".into(),
+        &Rope::default(),
         Default::default(),
     )
     .await
     .unwrap();
     fs.save(
         path!("/the/stdlib/src/string.rs").as_ref(),
-        &"".into(),
+        &Rope::default(),
         Default::default(),
     )
     .await
@@ -4072,7 +4072,7 @@ async fn test_file_changes_multiple_times_on_disk(cx: &mut gpui::TestAppContext)
     // to be detected by the worktree, so that the buffer starts reloading.
     fs.save(
         path!("/dir/file1").as_ref(),
-        &"the first contents".into(),
+        &Rope::from_str("the first contents", cx.background_executor()),
         Default::default(),
     )
     .await
@@ -4083,7 +4083,7 @@ async fn test_file_changes_multiple_times_on_disk(cx: &mut gpui::TestAppContext)
     // previous file change may still be in progress.
     fs.save(
         path!("/dir/file1").as_ref(),
-        &"the second contents".into(),
+        &Rope::from_str("the second contents", cx.background_executor()),
         Default::default(),
     )
     .await
@@ -4127,7 +4127,7 @@ async fn test_edit_buffer_while_it_reloads(cx: &mut gpui::TestAppContext) {
     // to be detected by the worktree, so that the buffer starts reloading.
     fs.save(
         path!("/dir/file1").as_ref(),
-        &"the first contents".into(),
+        &Rope::from_str("the first contents", cx.background_executor()),
         Default::default(),
     )
     .await
@@ -4805,7 +4805,7 @@ async fn test_buffer_file_changes_on_disk(cx: &mut gpui::TestAppContext) {
         marked_text_offsets("oneˇ\nthree ˇFOURˇ five\nsixtyˇ seven\n");
     fs.save(
         path!("/dir/the-file").as_ref(),
-        &new_contents.as_str().into(),
+        &Rope::from_str(new_contents.as_str(), cx.background_executor()),
         LineEnding::Unix,
     )
     .await
@@ -4837,7 +4837,7 @@ async fn test_buffer_file_changes_on_disk(cx: &mut gpui::TestAppContext) {
     // Change the file on disk again, adding blank lines to the beginning.
     fs.save(
         path!("/dir/the-file").as_ref(),
-        &"\n\n\nAAAA\naaa\nBB\nbbbbb\n".into(),
+        &Rope::from_str("\n\n\nAAAA\naaa\nBB\nbbbbb\n", cx.background_executor()),
         LineEnding::Unix,
     )
     .await
@@ -4889,7 +4889,7 @@ async fn test_buffer_line_endings(cx: &mut gpui::TestAppContext) {
     // state updates correctly.
     fs.save(
         path!("/dir/file1").as_ref(),
-        &"aaa\nb\nc\n".into(),
+        &Rope::from_str("aaa\nb\nc\n", cx.background_executor()),
         LineEnding::Windows,
     )
     .await