Device only runs Tiramisu (Android 13) currently
ROMs for this device:
LineageOS (Info about cheetah | LineageOS Wiki)
Spark OS
Ancient OS (only has a Telegram channel)
Paranoid Android
Evolution X
Stag OS
General XDA development forum for the device: https://forum.xda-developers.com/f/google-pixel-7-pro.12609/?prefix_id=33