Creating a visual script virtual function after minimizing crashes

[fire]

Godot version:
3cf3c41

OS/device including version:
Windows 10, gtx 1080

Issue description:
Using the test case from #23495 I was able to get the editor to crash.

Steps to reproduce:

1. Open a scene without a script (or not a loaded, empty scene)
2. Switch to script interface
3. Open res://Tscn/MainScene.tscn file with script
4. Need Fix empty script interface crash on tscn load. #23495 #23535 patch or crash
5. Minimize and then maximize the editor
6. Click the new function button.
7. Crash

Minimal reproduction project:

Same as #23495

[akien-mga]

Fixed by #23537.