Describe the bug

If the shift key is held down when an event sheet loses focus, the shift key will be held down in that event sheet.

So every time you click on an event or action, they will be multi-selected.

To Reproduce

1. open the event sheet.
2. hold down the Shift key and select the tab for the other scene.
3. Release the Shift key, and then return to the original event sheet.
4. Click on some of the events to see the problem.

This problem can also occur outside of the above steps.
For example, if you take a screenshot by pressing the windows 10 shortcut key "Shift + Win + S", this problem will occur.

It is difficult to notice that this problem is occurring.
This can lead to mistakes such as unintentionally deleting an event.

Other details

Desktop app
GDevelop 5.0.121