This is redundant in Python 3, and py2 is no longer supported.
No functional changes.

Generated using:
`find . -name '*.py' -print0 | xargs -0 sed -i 's/(object):/:/'`

In all cases:
 * The original type is one of
    `dict`, `dict_items`, `dict_keys` or `dict_values`.
 * The list is either iterated over or used to test `x in list`, then
    discarded.

These operations work identically on the original type, so the
 conversion is pointless.