By Megan Humphrey Manchester United have triggered Tottenham forward Celin Bizet’s release clause as she closes in on a move up north before the summer transfer window comes to a close. The 22-year-old played an instrumental role for Spurs last season, helping them write history by reaching the FA Cup final against the Red Devils in May. Both parties are hoping to finalise the deal before United fly out to Marbella for a pre-season training camp in the next week, according to BBC Sport. It’s understood Bizet has already undergone a medical at United after the club forked out around £600,000 to…