Bug with warnings about non-existent project settings

[dalexeev]

Godot version:
4.0.dev.calinou.d4d753552

OS/device including version:
Kubuntu 20.10

Issue description:
When switching between categories in the Project Settings, warnings appear randomly:

core/config/project_settings.cpp:240 - Property not found: application/run/name
core/config/project_settings.cpp:240 - Property not found: application/run/name
core/config/project_settings.cpp:240 - Property not found: application/run/name
core/config/project_settings.cpp:240 - Property not found: application/run/description
core/config/project_settings.cpp:240 - Property not found: application/run/description
core/config/project_settings.cpp:240 - Property not found: application/run/description
core/config/project_settings.cpp:240 - Property not found: application/run/icon
core/config/project_settings.cpp:240 - Property not found: application/run/icon
core/config/project_settings.cpp:240 - Property not found: application/run/icon
...

It looks like the name of one category is mixed with the properties of another category.
Apparently the bug appeared after #46127 or #45956. Perhaps this is due to a change in SectionedInspector.

Steps to reproduce:

1. Open the Project Settings Editor.
2. Switch categories on the left side of the window for a while until warnings appear in the output log.
3. No patterns have been identified in this bug; when switching to a specific category, warnings may or may not appear.

Minimal reproduction project:
—

[dalexeev]

Same problem with editor settings.

[Calinou]

I can't reproduce this on 4.0.alpha 174c147 (Linux) on an empty project.

[dalexeev]

On alpha 6, the bug is reproduced, although it has become quite rare:

I can't reproduce the bug on alpha 7. Either it has been fixed or it has become more rare.

[KoBeWi]

Also can't reproduce anymore.