Fix mypy errors in changes to recalculate_user_disk_usage()

lib/galaxy/model/__init__.py

@@ -1104,31 +1104,32 @@ WHERE user_id = :user_id and quota_source_label = :label
                     self.disk_usage = (self.disk_usage or 0) + amount
             else:
                 # else would work on newer sqlite - 3.24.0
-                engine = required_object_session(self).bind
-                if "sqlite" in engine.dialect.name:
+                sa_session = required_object_session(self)
+                assert sa_session.bind is not None
+                if "sqlite" in sa_session.bind.dialect.name:
                     # hacky alternative for older sqlite
-                    statement = """
+                    sql = """
 WITH new (user_id, quota_source_label) AS ( VALUES(:user_id, :label) )
 INSERT OR REPLACE INTO user_quota_source_usage (id, user_id, quota_source_label, disk_usage)
 SELECT old.id, new.user_id, new.quota_source_label, COALESCE(old.disk_usage + :amount, :amount)
 FROM new LEFT JOIN user_quota_source_usage AS old ON new.user_id = old.user_id AND NEW.quota_source_label = old.quota_source_label;
 """
                 else:
-                    statement = """
+                    sql = """
 INSERT INTO user_quota_source_usage(user_id, disk_usage, quota_source_label)
 VALUES(:user_id, :amount, :label)
 ON CONFLICT
     ON constraint uqsu_unique_label_per_user
     DO UPDATE SET disk_usage = user_quota_source_usage.disk_usage + :amount
 """
-                statement = text(statement)
+                statement = text(sql)
                 params = {
                     "user_id": self.id,
                     "amount": int(amount),
                     "label": quota_source_label,
                 }
-                with engine.connect() as conn, conn.begin():
-                    conn.execute(statement, params)
+                with sa_session.begin():
+                    sa_session.execute(statement, params)
 
     def _get_social_auth(self, provider_backend):
         if not self.social_auth: