TextureAtlas keep re-importing on every startup

[boruok]

Godot version

Godot_v4.0-beta1_win64

System information

Windows 11, GTX1060, Vulkan

Issue description

Tried to generate TextureAtlas from separate textures, on 3.x branch atlas generation happens only once,
in 4.x atlas auto generated each time when opening project.

Steps to reproduce

1. open attachment, notice that textures are reimporting
2. reload current project
3. textures are reimporting...

Minimal reproduction project

New Game Project.zip

[Daylily-Zeleen]

I meet this bug, too.
It's relate about multi threads importing.
In 3.5, default is single thread import. But in 4.0, default is multi threads import.
If disable multi threads import in source code and rebuild, it will work fine in 4.0 like 3.5.

[felbecker]

To keep things together: This is a duplicate of #54817 and apparently already fixed by #60888.