fix: Invalid Pydantic Definition On Group Model

[michael-genson]

What type of PR is this?

(REQUIRED)

• bug

What this PR does / why we need it:

(REQUIRED)

This week on "how did this used to work?", we replaced an invalid model field definition:

webhooks: list[Any] = []

...with two new ones:

class UpdateGroup(GroupBase):
  ...
  webhooks: list[CreateWebhook] = []

class GroupInDB(UpdateGroup):
  ...
  webhooks: list[ReadWebhook] = []

Which issue(s) this PR fixes:

(REQUIRED)

Fixes #3260

Special notes for your reviewer:

(fill-in or delete this section)

Maybe Pydantic used to automatically serialize unknown models into dicts? I have no idea.

Testing

(fill-in or delete this section)

Through the frontend I created a group, added/updated webhooks, and updated the group.

[hay-kot]

???? This makes no sense. Thanks for fixing this!