Fix bool registers in modbus integration (#41506)

When a register is of type bool modbus returns a whole byte, but ONLY the
lowest bit determine true/false.

homeassistant/components/modbus/binary_sensor.py

@@ -122,5 +122,5 @@ class ModbusBinarySensor(BinarySensorEntity):
             self._available = False
             return
 
-        self._value = result.bits[0]
+        self._value = result.bits[0] & 1
         self._available = True