Resource scripts in addons folder not appearing in resource creation menu

[SlashScreen]

Godot version

v4.0.stable.mono.official [92bee43]

System information

Windows 10

Issue description

When creating a custom resource (GDScript class inheriting Resource), scripts located underneath addons will not show up in the asset creation menu.

Steps to reproduce

When opening the project, attempt to create a NormalResource and see that it works. This script is located at res://normal_resource.gd.
Then, attempt to create an AddonsResource. See that, despite the code being nearly identical, it will not show up in the menu. This script is located under addons/foo/addons_resource.gd, to simulate being part of a package from the asset library.

Minimal reproduction project

resourcetest.zip

[SlashScreen]

I need to register my folder as a plugin for it to work. Whoops.

[Calinou]

See also #30048 and #27470.