Merge pull request swiftlang#21118 from benrimmington/remove-interval-group-info

[stdlib] Remove Interval.swift from GroupInfo.json

Author: moiseev

stdlib/public/core/GroupInfo.json

@@ -197,7 +197,6 @@
     "Bitset.swift"
   ],
   "Misc": [
-    "Interval.swift",
     "ErrorType.swift",
     "InputStream.swift",
     "LifetimeManager.swift",