moving the mouse outside of the window will still cause the window to update

**Describe the bug**

While the window has focus, moving the mouse outside of the window will still cause the window to update.
In multi-window applications, this problem causes slow updates when moving the mouse in another deferred viewport.
This issue does not appear in version 0.26.

https://github.com/emilk/egui/assets/50483832/69b2220c-1b73-4c69-9565-f28748482c15

**To Reproduce**
Steps to reproduce the behavior:
1. Focus on the main window or deferred viewport
2. Move the mouse outside the window

**Expected behavior**
Moving the mouse outside the window does not cause the window to update

**Desktop (please complete the following information):**
OS: Windows 10 LTSC 19044.3693
Version: 0.27.0 to master

Start by reproducing the behavior on Windows 10 with egui 0.27 or master, using the listed steps, and compare it with version 0.26. The issue is done when moving the mouse outside a focused window no longer causes updates, including in multi-window or deferred-viewport applications.

Written by the indexing model from the issue text.