“The Batman” isn’t trying to connect to everything DC has done at the movies since it formed the Justice League (who are still around — just don’t expect a get-together anytime soon). And the film is better for it. You won’t see star Robert Pattinson showing up in November’s multiverse tale “The Flash,” which stars both the O.G. Batman, Keaton, and the last actor to wear the cowl, Ben Affleck. And that’s how it should be.