After a quick google, neutering a snake may not be that easy.
For birth control purposes, removing the hemipenes would suffice. And they are removed when damaged without problems, not a major surgery. But..it would do nothing to prevent the instincts and urges.
For that the testicles would have to be removed. Which are in the abdominal area and that would require a far riskier and more involved surgery.
That may not completely remove the male aggression or instinct to breed 100% either. I have seen Geldings getting excited and even mounting mares. The instinct can still be there, even after a successful gelding, meaning both testicles and tissues were removed. Even worse with an aggressive animal, it doesn't always take the aggression away. For behavior and aggression issues it always works best if its done before the animal becomes sexually mature.
So then one would have to wonder, would it be worth the risk if the outcome may not be what was expected?
Perhaps in the future that is something that will become more commonplace?