Photo: Patrick Harbron/Disney Meryl Streep’s schedule presumably explains why Loretta, newly wedded to Martin Short’s Oliver, spends the first half of the latest Only Murders in the Building season off-screen. When she finally returns, the show demonstrates its knack for casually achieving magic even as it drifts into the comfortably familiar. Deep into her showcase episode, Loretta and Oliver duck into a small Brooklyn theater for a detour through his childhood. He recalls being a foster child