feat(myuplink): record NIBE F750 hardware validation

[segran2]

Summary

• record NIBE F750 in the MyUplink driver's tested model metadata
• bump the read-only driver from 1.2.2 to 1.2.3
• document the hardware evidence in the changelog
• no control or write path is added

Hardware evidence

Tested on a physical NIBE F750 connected to FTW through the existing MyUplink OAuth flow. FTW reported the connection as Connected and returned more than 100 live heat-pump telemetry points. Observed values included BT1 average outdoor temperature (13.70 °C during the validation) and BT12 condenser temperature (49.20 °C during the validation), along with climate-system and operating-state telemetry.

Credentials, device identifiers, private addresses and serial data are intentionally omitted.

Scope

This PR records compatibility/hardware evidence only. The existing MyUplink driver remains read-only and continues to fetch /v2/devices/{deviceId}/points; no F750-specific control behavior is introduced.