Fix the completions being too slow (#19013)

Closes https://github.com/zed-industries/zed/issues/19005

Release Notes:

- Fixed completion items inserted with a delay
([#19005](https://github.com/zed-industries/zed/issues/19005))

---------

Co-authored-by: Antonio Scandurra <antonio@zed.dev>

crates/editor/src/editor_tests.rs

@@ -7996,7 +7996,7 @@ async fn test_completion(cx: &mut gpui::TestAppContext) {
             .unwrap()
     });
     cx.assert_editor_state(indoc! {"
-        one.ˇ
+        one.second_completionˇ
         two
         three
     "});
@@ -8029,9 +8029,9 @@ async fn test_completion(cx: &mut gpui::TestAppContext) {
     cx.assert_editor_state(indoc! {"
         one.second_completionˇ
         two
-        thoverlapping additional editree
-
-        additional edit"});
+        three
+        additional edit
+    "});
 
     cx.set_state(indoc! {"
         one.second_completion
@@ -8091,8 +8091,8 @@ async fn test_completion(cx: &mut gpui::TestAppContext) {
     });
     cx.assert_editor_state(indoc! {"
         one.second_completion
-        two siˇ
-        three siˇ
+        two sixth_completionˇ
+        three sixth_completionˇ
         additional edit
     "});
 
@@ -8133,11 +8133,9 @@ async fn test_completion(cx: &mut gpui::TestAppContext) {
             .confirm_completion(&ConfirmCompletion::default(), cx)
             .unwrap()
     });
-    cx.assert_editor_state("editor.cloˇ");
+    cx.assert_editor_state("editor.closeˇ");
     handle_resolve_completion_request(&mut cx, None).await;
     apply_additional_edits.await.unwrap();
-    cx.assert_editor_state(indoc! {"
-    editor.closeˇ"});
 }
 
 #[gpui::test]
@@ -10142,7 +10140,7 @@ async fn test_completions_with_additional_edits(cx: &mut gpui::TestAppContext) {
             .confirm_completion(&ConfirmCompletion::default(), cx)
             .unwrap()
     });
-    cx.assert_editor_state(indoc! {"fn main() { let a = 2.ˇ; }"});
+    cx.assert_editor_state(indoc! {"fn main() { let a = 2.Some(2)ˇ; }"});
 
     cx.handle_request::<lsp::request::ResolveCompletionItem, _, _>(move |_, _, _| {
         let task_completion_item = completion_item.clone();