Remove the dead code that performs an early return with `if bases == (object,)` in `_coclass_meta`.

Whether it’s a remnant of Python 2.x or a legacy from the early stages of this project, there is dead code as shown below.

https://github.com/enthought/comtypes/blob/d80810b50eb642053b8dc1c3a2a4735bedf0a059/comtypes/_meta.py#L44-L62

If it can be confirmed that removing it poses no problems, I believe the codebase would be more readable without this section.

```diff
# the coclass' _com_interfaces_ list.
def __new__(cls, name, bases, namespace):
self = type.__new__(cls, name, bases, namespace)
- if bases == (object,):
- # HACK: Could this conditional branch be removed since it is never reached?
- # Since definition is `class CoClass(COMObject, metaclass=_coclass_meta)`,
- # the `bases` parameter passed to the `_coclass_meta.__new__` would be
- # `(COMObject,)`.
- # Moreover, since the `COMObject` derives from `object` and does not specify
- # a metaclass, `(object,)` will not be passed as the `bases` parameter
- # to the `_coclass_meta.__new__`.
- # The reason for this implementation might be a remnant of the differences
- # in how metaclasses work between Python 3.x and Python 2.x.
- # If there are no problems with the versions of Python that `comtypes`
- # supports, this removal could make the process flow easier to understand.
- return self
# XXX We should insist that a _reg_clsid_ is present.
if "_reg_clsid_" in namespace:
clsid = namespace["_reg_clsid_"]
```