Fix imports (OpenwaterHealth#182)

Author: sadhana-r

src/openlifu/db/session.py

@@ -199,7 +199,7 @@ def to_dict(self):
                 approval,
                 [asdict(t) for t in transforms],
             )
-        
+
         d['transducer_tracking_results'] = [asdict(t) for t in d['transducer_tracking_results']]
 
         return d

tests/test_database.py

@@ -16,7 +16,6 @@
 from openlifu import Point, Solution
 from openlifu.db import Session, Subject, User
 from openlifu.db.database import Database, OnConflictOpts
-from openlifu.db.session import ArrayTransform
 from openlifu.db.session import ArrayTransform, TransducerTrackingResult
 from openlifu.photoscan import Photoscan
 from openlifu.plan import Protocol, Run