Revert "Avoid excessive blocking of main thread when rendering in direct mode (#7253)" (#7272)

This reverts commit 020c38a891 because it
leads to glitches when selecting text.



https://github.com/zed-industries/zed/assets/1185253/78c2c184-bc15-4b04-8c80-a23ca5c96afa



Release Notes:

- N/A

crates/gpui/src/platform/mac/metal_renderer.rs

@@ -314,7 +314,7 @@ impl MetalRenderer {
         command_buffer.commit();
         self.sprite_atlas.clear_textures(AtlasTextureKind::Path);
 
-        command_buffer.wait_until_scheduled();
+        command_buffer.wait_until_completed();
         drawable.present();
     }