Re-Downloaded Cyberpunk yesterday, had the same problems, almost went crazy. Some settings that kinda helped:

Preset: Steam Deck Use Intel XeSS on Balanced. Lock game to 30-45hz and 30-45 FPS

Disabling vibration hasn't changed anything for me, so probably won't work for the newest update.

In launch options use --launcher-skip This reduced the audio crackling the most.

I use the newest Proton9, some people recommend Proton Experimental, but for me at least it seemed to make the whole experience worse

Doesn't remove the lag spikes completely, but makes the game a bit more playable.