The array API specification stipulates that

1. dim should accept a tuple of int's indicating all dimensions that should be squeezed.
2. dim should have no default value. Currently, not passing anything will squeeze all singleton dimension.

cc @ezyang @gchanan @mruberry @rgommers @pmeier @asmeurer @leofang @AnirudhDagar @asi1024 @emcastillo @kmaehashi