Watertown-bred actress Eliza Dushku has a new gig. Known for her roles in “Buffy the Vampire Slayer” and “Bring It On,” Dushku (inset) has been tapped to star opposite British actor Adam Rayner in a TV pilot reboot of “The Saint,” the ’60s series starring Roger Moore. (The show spawned a 1997 movie starring Val Kilmer.) Moore, the onetime James Bond actor, will coproduce the project with his son. Dushku just wrapped a movie called “The Scribbler” with Katie Cassidy and former porn star Sasha Grey.