AttributeError: 'NoneType' object has no attribute 'id', trying to remove a foreign key from a row or set it to null.

Describe the bug
A clear and concise description of what the bug is.

I need to be able to remove/null a foreign key. It is set to NOT NULL in the model. But seem to be having issues.

Ignoring exception in command: 'NoneType' object has no attribute 'id':
Traceback (most recent call last):
  File "/project/bombot/venv/lib/python3.10/site-packages/twitchio/ext/commands/core.py", line 217, in invoke
    await self._callback(*args, *context.args, **context.kwargs)
  File "/project/bombot/app/modules/cogs/bom_mod_commands.py", line 40, in remove
    await Player.get(name=playername).update(clan=None, enabled=False)
  File "/project/bombot/venv/lib/python3.10/site-packages/tortoise/queryset.py", line 1105, in __await__
    self._make_query()
  File "/project/bombot/venv/lib/python3.10/site-packages/tortoise/queryset.py", line 1082, in _make_query
    getattr(value, field_object.to_field_instance.model_field_name), None
AttributeError: 'NoneType' object has no attribute 'id'

To Reproduce
Steps to reproduce the behavior, preferably a small code snippet.

models.py:

class Clan(Model):
    id = fields.IntField(pk=True)
    name = fields.CharField(max_length=255, unique=True)
    tag = fields.CharField(max_length=4, unique=True)

class StatusManager(Manager):
    def get_queryset(self):
        return super(StatusManager, self).get_queryset().filter(enabled=True)

class Player(Model):
    id = fields.IntField(pk=True)
    name = fields.CharField(max_length=255, unique=True)
    clan = fields.ForeignKeyField('models.Clan', related_name='players', null=True)
    enabled = fields.BooleanField(default=True)

    enabled_players = StatusManager()

    def is_enabled(self) -> bool:
        return self.enabled

commands.py:

@commands.command()
    async def remove(self, ctx: commands.Context, playername: str) -> None:
        """
        !remove command
        """
        if (await Player.get(name=playername).exists()):
            if ((await Player.get(name=playername)).is_enabled()):
                await Player.get(name=playername).update(clan=None, enabled=False)
                await ctx.send(f"Removed @{playername} from their clan!")
            else:
                await ctx.send(f"@{playername} is not in a Clan roster!")
        else:
            await ctx.send(f"@{playername} does not currently exist!")

Expected behavior
A clear and concise description of what you expected to happen.

The field should be NULLED.

Additional context
Add any other context about the problem here.

Start in tortoise/queryset.py around _make_query, where the traceback reaches line 1082 while updating Player.clan. Reproduce the shown nullable ForeignKeyField update with clan=None, then verify that the foreign-key column is set to NULL without the AttributeError.