replace shallowCopy with move for ORC

[ringabout]

ref nim-lang/Nim#19972

it breaks nitter

2022-07-28T11:13:13.5379017Z �[1m�[36mTest "nitter" in category "nimble-packages"�[0m
2022-07-28T11:13:13.5379569Z �[1m�[31mFailure: reBuildFailed�[0m
2022-07-28T11:13:13.5380024Z nim c src/nitter.nim
2022-07-28T11:13:13.5380986Z Hint: used config file '/home/runner/work/Nim/Nim/config/nim.cfg' [Conf]
2022-07-28T11:13:13.5381782Z Hint: used config file '/home/runner/work/Nim/Nim/config/config.nims' [Conf]
2022-07-28T11:13:13.5391781Z Hint: used config file '/home/runner/work/Nim/Nim/pkgstemp/nitter/config.nims' [Conf]
2022-07-28T11:13:13.5392922Z ...........................................................................................................................................................................................
2022-07-28T11:13:13.5393785Z /home/runner/.nimble/pkgs/packedjson-#d11d167/packedjson.nim(325, 5) Error: undeclared identifier: 'shallowCopy'
2022-07-28T11:13:13.5394379Z candidates (edit distance, scope distance); see '--spellSuggest': 
2022-07-28T11:13:13.5394888Z  (4, 6): 'shallow' [proc declared in /home/runner/work/Nim/Nim/lib/system.nim(2799, 6)]
2022-07-28T11:13:13.5395390Z  (4, 6): 'shallow' [proc declared in /home/runner/work/Nim/Nim/lib/system.nim(2809, 6)]