Pumping lemma regular language can't be pumped
Have a look at the exact wording of the pumping lemma: It has a precondition that only words exceeding a certain size need to be pumpable. This is exactly so that only words with repetitions have to be pumpable.

For your language (and every other finite one) you can simply set that size beyond the maximum word size (e.g. at 4). No words are longer than that, and all of them can be pumped.