To my knowledge there's no such setting in AOSP, having combed through the system options in several major LineageOS (19 at the time) and CyanogenMod releases.
The only method I know is to delete the related file (I've also wiped the entire folder contents) in /system/product/media/audio/ui/
using root or alternative using the 'do not disturb mode' at all times.
The stock camera app (e.g. com.android.camera2
) may or may not have an option to turn off the shutter sound.