2023.10.0 - weather sensor setup errors

[PeteRager]

Describe the bug
During setup of weather sensors on S40 - errors are logged. The weather sensor do work.

To Reproduce
Steps to reproduce the behavior: Start the integration on an S40 system

Expected behavior
Expect no errors to be logged.

Screenshots/Logs
If applicable, add screenshots to help explain your problem.

2023-10-06 18:29:32.446 DEBUG (MainThread) [custom_components.lennoxs30.sensor_wt_env] async_added_to_hass WTEnvSensor myname [Lennox wt env humidity]
2023-10-06 18:29:32.446 ERROR (MainThread) [homeassistant.components.sensor] Error adding entities for domain sensor with platform lennoxs30
Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/helpers/entity_platform.py", line 507, in async_add_entities
    await asyncio.gather(*tasks)
  File "/usr/src/homeassistant/homeassistant/helpers/entity_platform.py", line 752, in _async_add_entity
    await entity.add_to_platform_finish()
  File "/usr/src/homeassistant/homeassistant/helpers/entity.py", line 1057, in add_to_platform_finish
    self.async_write_ha_state()
  File "/usr/src/homeassistant/homeassistant/helpers/entity.py", line 779, in async_write_ha_state
    self._async_write_ha_state()
  File "/usr/src/homeassistant/homeassistant/helpers/entity.py", line 879, in _async_write_ha_state
    state, attr = self._async_generate_attributes()
                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/helpers/entity.py", line 820, in _async_generate_attributes
    state = self._stringify_state(available)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/helpers/entity.py", line 785, in _stringify_state
    if (state := self.state) is None:
                 ^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/components/sensor/__init__.py", line 475, in state
    value = self.native_value
            ^^^^^^^^^^^^^^^^^
  File "/config/custom_components/lennoxs30/sensor_wt_env.py", line 186, in native_value
    return round(float(value), self._precision)
                 ^^^^^^^^^^^^
TypeError: float() argument must be a string or a real number, not 'NoneType'

Version

• Home Assistant: 2023.10.1
• This Integration: 2023.10.0

**Integration Configuration **

• Cloud or Local Connection: Local
• Inverter or Sensor Diagnostics Enabled: No

Additional context
Add any other context about the problem here.