You don't some people do breed year round.
Just like not everybody cools their snakes.
If you chose to cool your snakes however you will realize that is it easier to do so during the cool months of the year opposite trying to do it during the warmest month of the year. Same thing applies to photoperiod.
Bottom line there are many ways to do it you just need to find what’s right for YOU.
Also realize that is a lot of work and that not everyone wants to do that year round.