For all its incremental gestures toward inclusivity, "Saturday Night Live""now improbably in its 51st season"has remained curiously bereft of a regular South Asian cast member, a lacuna that feels less like oversight than inertia. Desi SNL, an ensemble-driven sketch revue, cheekily appropriating the familiar architecture of "Saturday Night Live""the opening monologue, the mock-news desk, the parade of quick-change ch…
