BME68x values never change

The environment sensor on the Thingy91x always reads the same value for the temperature, pressure, humidity, iaq, voc, and co2 sensors:

```
[00:00:34.319,213] environmental_module: sample: temp: 20.781536; press: 99331.265625; humidity: 32.830726; iaq: 50; CO2: 500.000000; VOC: 0.499999
...
[00:01:05.287,200] environmental_module: sample: temp: 20.781536; press: 99331.265625; humidity: 32.830726; iaq: 50; CO2: 500.000000; VOC: 0.499999
...
[00:04:05.678,894] environmental_module: sample: temp: 20.781536; press: 99331.265625; humidity: 32.830726; iaq: 50; CO2: 500.000000; VOC: 0.499999
```

## Testing setup

1. Download latest release: [hello.nrfcloud.com-v2.0.1-thingy91x-nrf91.hex](https://github.com/hello-nrfcloud/firmware/releases/download/v2.0.1/hello.nrfcloud.com-v2.0.1-thingy91x-nrf91.hex)
2. Use nRF Connect for Desktop and J-Link to flash the binary to Thingy91x
3. Use serial connection to device to observe logs of the environment data sensor

## Expected behavior

All readings should change each time data is fetched from the sensor.