It's a bit complex, but you can do it by sorting on a random number. I've implemented this in a reusable function below.
{randomizelist=(list) -> map(sort(map(list, x -> ["id":random(), "value":x]), (a,b) -> a.id - b.id), x -> x.value)}
{=randomizelist(["aaa", "bbb", "ccc", "ddd"])}
{=randomizelist(["aaa", "bbb", "ccc", "ddd"])}
{=randomizelist(["aaa", "bbb", "ccc", "ddd"])}
{=randomizelist(["aaa", "bbb", "ccc", "ddd"])}
{=randomizelist(["aaa", "bbb", "ccc", "ddd"])}