open-meteo fails when requesting the weather in the standard temperature units (Kelvin)

[jjacobowitz]

Prerequisites

Please confirm the following:

• I have searched open and closed issues to make sure it isn't already reported
• I reviewed the troubleshooting guide
• I reviewed InkyPi service logs and will paste any relevant logs below

Describe the bug
open-meteo does not appear to support temperature_unit=kelvin so the request fails.

Expected behavior
When setting the unit system to standard while using open-meteo the request should succeed and the temperature should be displayed in Kelvin.

To Reproduce
Steps to reproduce the behavior:

1. Set the weather provider to "Open-Meteo."
2. Set the units to "Standard (K)."
3. Save.
4. Force an update.

Logs

16:25:10 - ERROR - root - Failed to retrieve Open-Meteo weather data: b'{"error":true,"reason":"Data corrupted at path \'temperature_unit\'. Cannot initialize TemperatureUnit from invalid String value kelvin."}'
16:25:10 - ERROR - plugins.weather.weather - OpenMeteo request failed: Failed to retrieve Open-Meteo weather data.
16:25:10 - ERROR - refresh_task - Exception during refresh
Traceback (most recent call last):
  File "/home/InkyPi/src/plugins/weather/weather.py", line 109, in generate_image
    weather_data = self.get_open_meteo_data(lat, long, units, forecast_days + 1)
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/InkyPi/src/plugins/weather/weather.py", line 715, in get_open_meteo_data
    raise RuntimeError("Failed to retrieve Open-Meteo weather data.")
RuntimeError: Failed to retrieve Open-Meteo weather data.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/InkyPi/src/refresh_task.py", line 114, in _run
    image = refresh_action.execute(plugin, self.device_config, current_dt)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/InkyPi/src/refresh_task.py", line 279, in execute
    image = plugin.generate_image(self.plugin_instance.settings, device_config)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "home/InkyPi/src/plugins/weather/weather.py", line 118, in generate_image
    raise RuntimeError(f"{weather_provider} request failure, please check logs.")
RuntimeError: OpenMeteo request failure, please check logs.