chore(integration): bump hisense-unified-ac to main (diagnostics HA rendering)

Advance the integrations/hisense-unified-ac gitlink from the stale 12a7dd1
to the submodule main HEAD c0af4a7, which carries the full Phase-3 HACS
diagnostics rendering (sensor.py / binary_sensor.py / coordinator.py + the
options flow + the firmware<->HACS bit-contract test) plus the coordinator
read-timeout fix. This is the HA-visible consumer of the CompressorHz /
Features1 / Faults1 mfg-cluster attributes shipped in esp32 v1.1.4/v1.1.5;
const.py MFG_CLUSTER=0xFFF1FC00 and ATTR_{COMPRESSOR_HZ,FEATURES1,FAULTS1}
= 16/18/19 match both firmware paths byte-for-byte. Toward #39.

Assisted-by: AI

Author: AndrewDemsDS