Brian Laundrie, who is being hunted in connection to girlfriend Gabby Petito’s death, is “well versed” in surviving long periods of time in the wild, a former co-worker told The Post. Laundrie, 23, identified as a person of interest in Petito’s death during the couple’s cross-country trip, disappeared last week and is the subject of a massive manhunt at a 25,000-acre reserve near his Florida home. But Laundrie could prove hard to find — he once bragged to co-workers that he survived on just crackers for six weeks while camping, the co-worker said. “In conversation about hiking … Brian talked...