tests: try to avoid warnings about unawaited AsyncMock calls.

Using AsyncMock for objects causes all methods to be assumed async.
Override non-async methods that are known to be used by the tests.

tests/test_climate.py

@@ -30,6 +30,7 @@ async def test_init_entry(hass):
     # AsyncMock, it expects us to await the result.
     m_add_entities = Mock()
     m_device = AsyncMock()
+    m_device.get_property = Mock(return_value=None)
 
     hass.data[DOMAIN] = {}
     hass.data[DOMAIN]["dummy"] = {}

tests/test_device.py

@@ -376,6 +376,7 @@ class TestDevice(IsolatedAsyncioTestCase):
         self.subject.receive_loop = AsyncMock()
         self.subject.receive_loop.return_value = "LOOP"
         self.hass().bus.async_listen_once.return_value = "LISTENER"
+        self.hass().async_create_task = Mock()
         self.subject._running = False
 
         # run the function under test

tests/test_text.py

@@ -27,6 +27,7 @@ async def test_init_entry(hass):
     )
     m_add_entities = Mock()
     m_device = AsyncMock()
+    m_device.get_property = Mock(return_value=None)
 
     hass.data[DOMAIN] = {
         "dummy": {"device": m_device},