Update sourcekit-xfails.json: SR-8568 was resolved

Author: Nathan Hawes

sourcekit-xfails.json

@@ -645,13 +645,6 @@
     "offset": 145,
     "issue": "https://github.com/apple/swift/pull/18198 (fixed on master; rdar://problem/41100570)"
   },
-  {
-    "branches": ["master"],
-    "file": "Re-Lax/ReLax/ReLax/DataHelpers.swift",
-    "offset": 2230,
-    "request": "CodeComplete",
-    "issue": "https://bugs.swift.org/browse/SR-8568"
-  },
   {
     "branches": ["master"],
     "failure": "crashed",