removed unused import and minor syntax

tests/app/dao/test_annual_billing_dao.py

@@ -1,9 +1,8 @@
 from app.dao.date_util import get_current_financial_year_start_year
-from app.models import AnnualBilling
+
 from app.dao.annual_billing_dao import (
     dao_create_or_update_annual_billing_for_year,
     dao_get_free_sms_fragment_limit_for_year,
-    dao_get_annual_billing,
     dao_update_annual_billing_for_current_and_future_years,
 )
 from tests.app.db import create_annual_billing