PHILADELPHIA — Republican David McCormick ended his primary campaign against GOP rival Mehmet Oz on Friday night, conceding a closely contested race as a recount showed no signs of shifting the outcome in McCormick’s favor. McCormick, speaking to supporters in Pittsburgh, said he called Oz to congratulate him and would support his onetime rival in the general election against the Democratic nominee, Lt. Gov John Fetterman. “It’s now clear to me, with the recount largely complete, that we have a nominee,” McCormick said. Oz, the celebrity surgeon known as “Dr. Oz,” will now move forward as the …