Constance doesn't support config values of the type <class 'dict'>

[morrah]

Describe the problem

Constance doesn't support config values of the type <class 'dict'>. Please fix the value of 'MY_VAR'

Error message comes from forms.py, FIELDS dictionary lacks of new collection-types.

Steps to reproduce

CONSTANCE_CONFIG = {
    'MY_VAR': ({'test': 432}, 'my test var', dict),
}

System configuration

• Django version: 4.1.2
• Python version: 3.11.0rc1
• Django-Constance version: 4.1.2