Crash when importing a custom type with list<enum>

Describe the bug

Tiled crashes when loading an external custom types export which contains a type with:

• an enumerate
• a list containing the same enumerate
• a boolean
• a list of boolean

(not sure about the exact combination though)

Steps to reproduce

1. Create new Tiled project
2. Open custom types editor and create a new custom type like so:

3. Export custom types to an external file (reference_export.json)
4. Close Tiled
5. Open Tiled and create a new project
6. Load the custom types export (reference_export.json)
7. It loads fine, custom types editor is still open
8. In custom types editor, click on "TopLevelType" definition
9. Tiled application crashes
10. Re-open the same Tiled project
11. A warning is displayed saying there is a circular reference

12. Open custom types editor and navigate to "TopLevelType" definition again
13. It does not crash but "list_of_enums" field does not contain anything

For reference, here is the export file causing the issue: reference_export.json

For reproduction, I believe you can start at step n°5 and just load the export file.

Expected behavior

We should be able to load this kind of file.
At least, application should not crash.

OS version

Windows 11

Tiled version

1.12.2