The “DUI Saturation Patrols” we normally associate with Saint Patrick’s Day and Super Bowl Sunday will be rolling out for this Saturday’s 4/20 observances, as SFPD hopes to discourage people from driving while stoned. SFist has many times reminded you the times when the SF Police Department was planning DUI checkpoints. These are usually scheduled for popular drinking holidays, like Saint Patrick’s Day or Super Bowl Sunday. But this year they’re…