By Jon Wertheim The 21-year-old continued her dominance with a commanding win over Coco Gauff in Paris to capture her second Grand Slam trophy. PARIS — As Iga Świątek grasped the trophy after winning her second French Open title in two years, the skies opened, but for the previous 68 minutes, she provided all the thunder and lightning. In a thoroughly dominating performance, the No. 1 seed lived up to her billing, beating Coco Gauff, 6-1, 6-3 in a much-anticipated final. This marked the 35th straight win, dating back to February, and the sixth consecutive title for Świątek, yet another indicat…