Is General Mark Milley guilty of treason?

Following the January 6th riots, General Mark Milley secretly contacted a Chinese general and warned him that Trump might “go rogue” and attack China. This story was initially dismissed (even by Trump) but has been found to be true. Republicans are calling on Milley to resign for undermining the sitting president, others are going as far as accusing him of Treason. What do you think should happen to him?