always_on_top breaks non-embedded popups

[Ayush0Chaudhary]

Godot version

307dfa9

System information

Windows 10 x64

Issue description

I guess sub-windows should inherit the always_on_top flag.

Steps to reproduce

1. Add any node with popup menu (e.g. TextEdit)
2. Enable always_on_top in project settings
3. Disable embed_subwindows
4. Run
5. Open the popup menu (right-click TextEdit etc)

Minimal reproduction project

No response