Can't handle strings and floats

[oscgonfer]

When a sensor gives null as a result, we can't handle it if we use pydantic models:

ValidationError: 1 validation error for Device
data.sensors.22.value
  Input should be a valid number, unable to parse string as a number [type=float_parsing, input_value='null', input_type=str]
    For further information visit https://errors.pydantic.dev/2.8/v/float_parsing