DETROIT — For generations, the career path for smart kids around Detroit was to get an engineering or business degree and get hired by an automaker or parts supplier. If you worked hard and didn’t screw up, you had a job for life with enough money to raise a family, take vacations and buy a weekend cottage in northern Michigan. Now that once-reliable route to prosperity appears to be vanishing, as evidenced by General Motors’ announcement this week that it plans to shed 8,000 white-collar jobs on top of 6,000 blue-collar ones. It was a humbling warning that in this era of rapid and disruptive technological change, those with a college education are not necessarily insulated from the kind of layoffs factory workers know all too well. Tech taking over The cutbacks reflect a transformation underway in both the auto industry and the broader U.S.