LOS ANGELES—Attorneys for Alec Baldwin and other producers of the movie “Rust” are asking a court to dismiss a civil lawsuit filed by a script supervisor who was on the set when the actor fatally shot a cinematographer. In a filing in Los Angeles Superior Court on Monday, the attorneys said the claim by Mamie Mitchell should be thrown out because there was no evidence that Baldwin or any of the producers intended harm. Baldwin was the lead actor and a producer of the independent film, a Western. “Despite Plaintiff’s attempt to label claims as intentional, nothing about Plaintiff’s allegations suggest that any of Defendants intentionally committed harmful conduct,” the filing said. Mitchell claimed in a lawsuit filed in November that Baldwin should have checked the Colt .45 revolver he was holding to make sure it did not include live ammunition. Baldwin has said the assistant director told him the …