test: remove unused imports

program/tests/test_services.py

-from datetime import datetime, timedelta
+from datetime import datetime
 
 import pytest
 
 from django.utils.timezone import make_aware
 from program.models import TimeSlot
-from program.services import generate_conflicts, generate_timeslots, make_conflicts
+from program.services import generate_conflicts, generate_timeslots
 from program.tests.factories import TimeslotFactory
-from program.tests.test_schedules import schedule_data
-from program.tests.test_schedules import url as schedule_url
-from program.typing import ScheduleData
 
 pytestmark = pytest.mark.django_db