A conservative commentator splashed cold water on speculation that Donald Trump would back out of his first debate against president Joe Biden. Democratic strategist James Carville wagers that Trump won’t take the stage with Biden, but former Republican congressional staffer Amanda Carpenter told MSNBC’s “Morning Joe” the presumptive GOP nominee wouldn’t pass up a chance to spew lies and inflict pain on his Democratic rival. “I’m not a betting woman, but I would happily take the other side of James Carville’s wager for the exact point that Donald Trump will not turn down an opportunity for con…