Ignore touchpad gestures if KWIN_IGNORE_TOUCHPAD_GESTURES is set
There are some users that would like to configure their touchpad gestures themselves but if they try using libinput-gestures KWin still activates the built-in gestures. So until there is a way to configure the gestures in Plasma this environment variable can be used to disable KWins touchpad gestures.
This is not really a bugfix but I'd still like to cherry-pick this to 5.20.5