Add 100% test coverage to Madvr (#122350)

* feat: add 100% test coverage

* fix: dont patch logger

* fix: better names

* fix: use consts

* fix: use built in const

homeassistant/components/madvr/sensor.py

@@ -58,7 +58,7 @@ def get_temperature(coordinator: MadVRCoordinator, key: str) -> float | None:
     """Get temperature value if valid, otherwise return None."""
     try:
         temp = float(coordinator.data.get(key, 0))
-    except ValueError:
+    except (AttributeError, ValueError):
         return None
     else:
         return temp if is_valid_temperature(temp) else None