gh-152156: Fix a crash in interpeters.create under limited memory conditions

[sobolevn]

In handle_channel_error we already set an error. When called the second time, we get end up with err == 0 and run this code:

if (err == 0) {
    assert(!PyErr_Occurred());
    return 0;
}

which will fail, because exception was already set by the first error. So, there's no need to call it twice.

• Issue: Fix error handling in Modules/_interpchannelsmodule.c #152156

[serhiy-storchaka]

Are you sure that channel_destroy can not clear error?

[sobolevn]

PyErr_Clear can be called in _release_xid_data under XID_IGNORE_EXC, but it resets the previous error correctly. I don't see any real ways to clear it.

PyErr_GetRaisedException and PyErr_Clear are only used in _release_xid_data in this path.