fix: delay import for orm, in case SA not installed

src/wuttjamaican/auth.py

@@ -29,8 +29,6 @@ This defines the default :term:`auth handler`.
 import secrets
 import uuid as _uuid
 
-from sqlalchemy import orm
-
 from wuttjamaican.app import GenericHandler
 
 
@@ -110,6 +108,8 @@ class AuthHandler(GenericHandler):
         :returns: :class:`~wuttjamaican.db.model.auth.User` instance,
            or ``None``.
         """
+        from sqlalchemy import orm
+
         model = self.app.model
 
         try: