coder currently expects OIDC claims to be in the string array format. this is problematic when users are only assigned to 1 group or 1 role, because the IdP will return the claims as type string:

coderd: groups field was an unknown type  request_id=ef72ff07-9550-4ccf-9461-a7caa69c7051  type=string

we validated this by successfully logging into Coder as a user who is assigned to 2 groups, with the groups being synced correctly.