Revert "Invalidate tooltips when mouse leaves element's hitbox (#22488)" (#22542)

This reverts commit 344284e013.

That change broke git blame tooltips, as Zed should also show tooltips
which are hovered, even though the mouse had left the origin element's
bounds.

Release Notes:

- N/A

crates/gpui/src/elements/div.rs

@@ -1417,19 +1417,6 @@ impl Interactivity {
                             None
                         };
 
-                        let invalidate_tooltip = hitbox
-                            .as_ref()
-                            .map_or(true, |hitbox| !hitbox.bounds.contains(&cx.mouse_position()));
-                        if invalidate_tooltip {
-                            if let Some(active_tooltip) = element_state
-                                .as_ref()
-                                .and_then(|state| state.active_tooltip.as_ref())
-                            {
-                                *active_tooltip.borrow_mut() = None;
-                                self.tooltip_id = None;
-                            }
-                        }
-
                         let scroll_offset = self.clamp_scroll_position(bounds, &style, cx);
                         let result = f(&style, scroll_offset, hitbox, cx);
                         (result, element_state)