Moon Altar Spawning Bugged

When mining the dead Celestial Champion, the altar pieces will occasionally spawn like this, which looks very odd.

This is because it's spawning code is not working properly, and detects items and other such regular entities as being blockers.

local PIECEBLOCKER_CANT = {"INLIMBO", "FX", "DECOR", "NOCLICK", "flying", "ghost", "playerghost"}
local function altarpiece_spawn_checkfn(v)
    local ents = TheSim:FindEntities(v.x, v.y, v.z, 1.5, nil, PIECEBLOCKER_CANT)
    return #ents == 0
end

This is because in the altarpiece_spawn_checkfn function in alterguardian_phase3dead that's passed into FindWalkableOffset, it's using the PIECEBLOCKER for the canttags parameter in TheSim:FindEntities. This means it returns all entities BUT the defined blockers in the list of tags, meaning it'll count items, and other entities that aren't actual blockers.

Instead PIECEBLOCKER_CANT should be passed to the 5th parameter, after the 1.5 (and also rename to PIECEBLOCKER_CAN :p)