Disabling the LED of a webcam (tested on Ubuntu 22) (Source)
# Get the right device
v4l2-ctl --list-devices
# Get the current setting
v4l2-ctl --get-ctrl=led1_mode -d /dev/video4
# Disable the LED
v4l2-ctl --set-ctrl=led1_mode=0 -d /dev/video4