Filmmaker Steven Spielberg always moves fluidly from genre to genre, and perhaps there’s no better example than the recent 30th anniversary of 1993’s “Schindler’s List,” which was released the same year as the couldn’t-be-totally-different “Jurassic Park.” And so, coming off his grounded and very personal family drama, “The Fabelmans,” for his next film, Spielberg might be going back to the sci-fi genre again.