NEWTOWN SQUARE, Pa. — Dustin Johnson knows where he will be this weekend and that is what he is focused on at the moment. Next year? Not so sure. Johnson, the two-time major champion and one of LIV Golf’s biggest early signings, was a surprise invite to this year’s PGA Championship, the lowest-ranked player in the field aside from the 20 PGA of America club pros. As a former No. 1-ranked player in the world (now 471st) who also had a 12–9 record across five Ryder Cups and is exempt for next month’s U.S. Open, the invite might not have been so surprising—especially when you consider the PGA of America granted 33 special invitations. Johnson’s game has fallen off over the past two years, which made his par-70 effort on Friday a welcome result in difficult conditions, one good enough to make the 36-hole cut and play the weekend.…