Revert "Hide the mouse when the user is typing in the editor (#25040)" (#25393)

This reverts commit a8610fbd13.

I've been seeing some reports of segmentation faults that appear to
point to this change as the culprit.

Closes #25366.

Release Notes:

- Community: Reverted #25040, so remove the corresponding entry from the
release notes.

crates/gpui/src/platform/linux/platform.rs

@@ -666,12 +666,6 @@ impl CursorStyle {
             CursorStyle::DragLink => "alias",
             CursorStyle::DragCopy => "copy",
             CursorStyle::ContextualMenu => "context-menu",
-            CursorStyle::None => {
-                #[cfg(debug_assertions)]
-                panic!("CursorStyle::None should be handled separately in the client");
-                #[cfg(not(debug_assertions))]
-                "default"
-            }
         }
         .to_string()
     }