Riz Ahmed took aim at the British during his opening monologue as host on “Saturday Night Live U.K.” on April 4. “We like it when things are a little bit crap,” he said. Ahmed started with a dig at his own eclectic credit list: “I’m an actor, I’m a writer, I’m a producer, and I’m a rapper. So for those of you who don’t know who I am, clearly, neither do I. I’m working it out.” He referenced his Oscar-nominated performance in “Sound of Metal,” and his part as a terrorist in the comedy “Four