A new or factory-reset iot device can report a clock far in the past,
e.g. year 2000, which causes a failure in timezone autodetection
logic as the difference can be in years.
This causes `update()` to fail, so every cli command fails, including
`wifi scan` and `wifi join`, which are the commands needed to provision
the device.
To fix this, this changes the logic fall back to UTC if the device clock is not set,
detected by checking if the timedelta is too large.
Co-authored-by: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
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