OpenStack Swift auth_version verification fails

Version: TrueNAS-12.0-U1.1

TrueNAS cloudcredential verification fails with the not overwriteable default version settings.

Error:
```
Error: Traceback (most recent call last):
File "/usr/local/lib/python3.8/site-packages/middlewared/main.py", line 137, in call_method
result = await self.middleware._call(message['method'], serviceobj, methodobj, params, app=self,
File "/usr/local/lib/python3.8/site-packages/middlewared/main.py", line 1195, in _call
return await methodobj(*prepared_call.args)
File "/usr/local/lib/python3.8/site-packages/middlewared/schema.py", line 973, in nf
return await f(*args, **kwargs)
File "/usr/local/lib/python3.8/site-packages/middlewared/plugins/cloud_sync.py", line 547, in verify
await self._validate("cloud_sync_credentials_create", data)
File "/usr/local/lib/python3.8/site-packages/middlewared/plugins/cloud_sync.py", line 638, in _validate
raise verrors
middlewared.service_exception.ValidationErrors: [EINVAL] cloud_sync_credentials_create.attributes.auth_version: Invalid choice: 3
```

How to replicate:

• create new cloud credentials

• select OpenStack Swift as provider

• Provide bogus information to every field required

• click "verify credential"

• Optional: select different AuthVersion values