Fixes issue [#24078](https://github.com/ansible/ansible/issues/24078)
Resource pools are retrieved from VSphere regardless of the state of the `resource_pool` parameter. During this process, each retrieved Resource Pool is checked for the `parent` attribute, and if it exists, the currently-scoped parent object is compared against the Resource Pool's parent object. The method doing the check, however, `assert`s that the parent object is not `None`. In some cases, a Resource Pool will have the `parent` attr, but that `parent` object will be `None`, causing the `assert` to fail.
This should avoid that. :-)
1c11a35f70