Adam B. Vary Senior Entertainment WriterJean-Luc is getting the old gang back together.“Star Trek: The Next Generation” stars LeVar Burton, Michael Dorn, Jonathan Frakes, Gates McFadden, Marina Sirtis and Brent Spiner will join Patrick Stewart for the third and final season of the Paramount Plus series “Star Trek: Picard.”Spiner has played several characters on “Picard” in Season 1 and 2 (which is currently streaming), including his original role of the android Data; Frakes and Sirtis appeared in one memorable episode of “Picard” in Season 1 as William T.