Move win_xfa_clang bot back into regular commit queue

win_xfa_clang bot was marked as experimental due to
https://crbug.com/626120 which was fixed a while ago.
Now no longer need to keep it as experimental.

Review-Url: https://codereview.chromium.org/2363603002
diff --git a/infra/config/cq.cfg b/infra/config/cq.cfg
index 6d9b577..a06c1c6 100644
--- a/infra/config/cq.cfg
+++ b/infra/config/cq.cfg
@@ -66,7 +66,6 @@
       }
       builders {
         name: "win_xfa_clang"
-        experiment_percentage: 100
       }
     }
   }