eBay's board of directors has formally rejected GameStop's unsolicited bid to acquire the e-commerce company, bringing an unceremonious end to one of the stranger corporate stories of the year. In a press release issued Tuesday morning , eBay's board called the proposal from GameStop CEO Ryan Cohen "neither credible nor attractive," citing concerns about GameStop's financing plan, the operational risks of a combined company, and questions about GameStop's own governance and executive incentives. The rejection letter, signed by eBay board chairman Paul Pressler, was unambiguous. The board said it had considered eBay's standalone prospects and concluded that the company was better positioned on its own, with a clear strategy and management team already in place. For anyone who has been following this saga, eBay's skepticism was entirely predictable.…