fix: allow nested models named attributes to be serialized

[fakalit]

https://community.forestadmin.com/t/collections-unable-to-preview-collection-items-due-to-serialization-issues/5359/4

If there a nested model named "attributes" serialization fails. While the actual bug seems to be in JSONSerializer (it makes the assumption of: an object having the key "attributes" means it's a schema.), adding the words "attributes" to the reserved keywords on the forest side seems to fix this problem.

Definition of Done

General

• [X] Write an explicit title for the Pull Request, following Conventional Commits specification
• [X] Test manually the implemented changes
• [X] Validate the code quality (indentation, syntax, style, simplicity, readability)

Security

• [X ] Consider the security impact of the changes made

[SkyHuss]

Hello again ! The fix has been released #961 , so I close this PR, thanks again for your contribution 🙏