Travis Kelce’s ex-girlfriend, Kayla Nicole, was caught mingling with Patrick Mahomes’ brother Jackson in Las Vegas, RadarOnline.com has learned. While the Kansas City Chiefs quarterback and his wife, Brittany, are no longer close with Nicole since her breakup from Kelce, his embattled brother seems to have kept in touch — and the two decided to hit up Super Bowl festivities in Sin City together ahead of Sunday’s big game. Eyewitnesses dished Nicole and Jackson ran into each other at Aria’s High Limit Lounge at around 10:15 PM on Thursday. Tipsters said Kelce’s ex-girlfriend, whom he dated on a…