The PGA Tour ended its expensive fight with Saudi Arabia’s golf venture and now is joining forces with it, making a stunning announcement Tuesday of a merger that creates a commercial operation with the Public Investment Fund and the European tour.As part of the deal, the sides immediately are dropping all lawsuits involving LIV Golf.From the golf side, still to be determined is how players like Brooks Koepka and Dustin Johnson can rejoin the PGA Tour after defecting last year for signing bonuses reported to be in …