Initial Superuser can get in a "stuck" state

Describe the bug
If a super user is created but then - say, because they get distracted watching Galaxy of Terror 😅 - gets logged out without creating a team, they're stuck. They can't authenticate again that way because they aren't on a team, they never created one.

To Reproduce
Steps to reproduce the behavior:

Set up an empty portr instance
Log in and create the first superuser but DO NOT create a team
Delete cookie for session
Attempt to Log in again
See error message

Expected behavior
Superuser can log in even if they aren't on a team - so they can create a team

Screenshots

Error message is shown User not part of any team

Additional context
Fixed as part of #25 but there's a number of other changes there..

Is the first user getting stuck? This solves it, right?

portr/admin/src/portr_admin/main.py

Lines 60 to 62 in 0042a49

    
           first_team = await user.teams.filter().first() 
        
           if first_team is None: 
        
               return RedirectResponse(url="/new-team")

That kind of check could work but that would just redirect the user after they're logged in.

The issue is that the user cannot log back in again - if they're logged out they're not able to log back in without an error message.

	first_team = await user.teams.filter().first()
	if first_team is None:
	return RedirectResponse(url="/new-team")