I've used https://wago.io/xu1ybQZDZ and modified it slightly to fit a different need/want - original WA credit to Zyim's Auto Roll Weak Aura.
I modified this weak aura to perform the following actions in WotLK 25 man raids, and have a separate one for 10 man raids as my guild does loot differently between the two.
This version is set to load during 25 man raids and will auto Greed on Greens/Blues while Passing on Epics.*NOTE* Your raid loot holder will need to make sure they go into custom configuration and set EPICS to DO NOTHING, so they can still interact with the items, and not have 25 players all auto pass and forget the loot.
After testing in a heroic run - the roll on BOP items still pops up the loot confirmation window, but that can be bypassed by using Leatrix Plus addon, and using /ltp > System > Disable loot warnings, this option disables confirmation window when choosing a loot roll option or attempting to sell/mail trade able items.
*Note that on final bosses in heroic dungeon testing, it auto rolls on the frost orb, and typically the blue item, but still have to manually greed/need/pass the epic item that drops. Not sure how to fix that yet for multiple BoP item drops.
So for your raid loot holder, they'll still have to click all 4+ boss drops unfortunately until a workaround is figured out for this.
Otherwise, works 90% how i want/need it to thus far and I'm happy with that. This is just how my guild does our loot so I wanted to make it quicker for the raid and eliminate the 4 item pop ups every time, as well as ignore the trash items that are looted.