The Biden campaign is rebuking the GOP for its decision to allow Dana White to speak at next week’s Republican convention in Milwaukee in the moments before Donald Trump accepts the party’s nomination. White, the powerful chief executive of Ultimate Fighting Championship, will be the penultimate speaker at the convention on its final night in a move that highlights his tight friendship with Trump, it was confirmed on Wednesday evening. It is also a controversial choice. On New Year’s Eve in 2022, White was caught on camera viciously slapping his wife Anne during a heated argument at a bar in M…