Start thermal collection in BMCWeb to actually launch tlBMC Thermal Control

Tested:
Manually verified:
```
root@pnhuna-mfae4-bmc-01:/tmp# journalctl -u bmcweb
...
Dec 12 15:54:48 pnhuna-mfae4-bmc-01.prod.google.com bmcweb[19338]: W1212 15:54:47.190554   19348 zone_manager.cc:161] [Thermal]: Sensor `HPM0_CPU_T` in zone `1` is missing.
...
```

#pid-tlbmc-migration

PiperOrigin-RevId: 843911128
Change-Id: I7b537f2e65db79d457a388385b22909a53b35bd1