Fix namespace-import pylint warning in shelly tests (#119349)

tests/components/shelly/__init__.py

tests/components/shelly/conftest.py

tests/components/shelly/test_binary_sensor.py

tests/components/shelly/test_climate.py

tests/components/shelly/test_coordinator.py

tests/components/shelly/test_device_trigger.py

tests/components/shelly/test_init.py

tests/components/shelly/test_logbook.py

tests/components/shelly/test_number.py

tests/components/shelly/test_sensor.py

tests/components/shelly/test_switch.py

tests/components/shelly/test_update.py