Make ctypes.Array abstract (#6361)

Co-authored-by: Akuli <akuviljanen17@gmail.com>

tests/stubtest_allowlists/py3_common.txt

@@ -73,6 +73,8 @@ csv.Dialect.lineterminator
 csv.Dialect.quoting
 csv.Dialect.skipinitialspace
 ctypes.Array.__iter__  # mypy doesn't support using __getitem__ instead of __iter__ so this is here https://github.com/python/mypy/issues/2220
+ctypes.Array._type_  # _type_ and _length_ are abstract, https://github.com/python/typeshed/pull/6361
+ctypes.Array._length_
 ctypes.CDLL._FuncPtr  # None at class level but initialized in __init__ to this value
 ctypes.memmove  # CFunctionType
 ctypes.memset  # CFunctionType