Remove the old removal logics from Torbutton
torbutton@2dfa0e0c introduced some logic to remove old files (
$profile/cookies|protected-*.json) that aren't used anymore.
However, after the 12.0 watershed, we don't need it for sure anymore.
Also, there is a function to mess with preferences that we don't need anymore.
So, as part of the great torbutton cleanup, remove all of this.