Virginia City’s annual salute to spring arrives Saturday on the Comstock. The 22nd annual Rocky Mountain Oyster Fry — also known as the Testicle Festival — and St. Patrick’s Day Parade returns 10 a.m.-4 p.m. Saturday. Each year, about 20 cooks stir up culinary masterpieces featuring mountain oysters — the tasty byproduct of bull castration. The cooking and tasting goes from 10 a.m.-5 p.m. in the Delta Saloon parking lot next to the Bucket of Blood. “Rocky Mountain Oysters are kind of a unique experience,” said Allyson Reedland, of RKPR which promotes the event. “They’re not for everyone. But if …