[Stress tester XFails] Update XFails

- SR-15502 has been fixed on main

Author: ahoppen

sourcekit-xfails.json

@@ -820,18 +820,6 @@
     ],
     "issueUrl" : "https://bugs.swift.org/browse/SR-15499"
   },
-  {
-    "path" : "*\/Base64CoderSwiftUI\/Base64CoderSwiftUI\/ContentView.swift",
-    "modification" : "unmodified",
-    "issueDetail" : {
-      "kind" : "codeComplete",
-      "offset" : 2029
-    },
-    "applicableConfigs" : [
-      "main"
-    ],
-    "issueUrl" : "https://bugs.swift.org/browse/SR-15502"
-  },
   {
     "path" : "*\/ACHNBrowserUI\/ACHNBrowserUI\/ACHNBrowserUI\/packages\/Backend\/Sources\/Backend\/services\/NotificationsManager.swift",
     "modification" : "unmodified",