I am considering becoming a pediatrician, and I am wondering if I would be required to circumcise babies during my training?

Only if you want to. Some programs will teach circumcision, but most leave it to the obstetricians. More parents are opting not to circimcise, so if you want to learn, you can, but no one will force you to.
Service provider. Depending on the program, you will be expected too learn those procedures normally performed by a pediatrician.This will include at least one method of circumcision.In my region the pediatrician performs the circumcisions.If you are against providing this service when requested, you should stay out of general peds but consider a peds subspecialty that avoids the issue.There are many available.
Circumcise. Required? Probably no. Some programs don't even teach it. Most programs teach it if you want to learn it.
Not required. Most newborn circumcisions in us are performed by obstetricians. Pediatric urologists and pediatric surgeons, by and large do a better job. Fewer & fewer pediatricians do circumcisions. Firstly, most don't want to do it. Secondly they have to pay much more for malpractice insurance, so it is only financial viable if a pediatrician performs lots of them. You are safe either way. Good luck.