chore: update development dependencies and improve test coverage

- Upgraded `pytest-asyncio` to version 1.0 to ensure compatibility with the latest features and improvements.
- Increased the coverage threshold in pytest configuration to 80%, enhancing the quality assurance process.
- Added a new `conftest.py` file to manage shared fixtures and improve test organization.
- Introduced multiple new test files to cover various components, ensuring comprehensive test coverage across the application.
- Updated the `.coverage` file to reflect the latest coverage metrics.

duty_teller.egg-info/SOURCES.txt

@@ -37,13 +37,24 @@ duty_teller/utils/__init__.py
 duty_teller/utils/dates.py
 duty_teller/utils/handover.py
 duty_teller/utils/user.py
+tests/test_api_dependencies.py
 tests/test_app.py
+tests/test_calendar_ics.py
 tests/test_calendar_token_repository.py
 tests/test_config.py
+tests/test_db_session.py
 tests/test_duty_schedule_parser.py
+tests/test_group_duty_pin_service.py
+tests/test_handlers_commands.py
+tests/test_handlers_errors.py
+tests/test_handlers_group_duty_pin.py
+tests/test_handlers_init.py
 tests/test_i18n.py
 tests/test_import_duty_schedule_integration.py
+tests/test_import_service.py
+tests/test_package_init.py
 tests/test_personal_calendar_ics.py
 tests/test_repository_duty_range.py
+tests/test_run.py
 tests/test_telegram_auth.py
 tests/test_utils.py