Collections stuck as PlexPartialObject after reloading

[JonnyWong16]

Describe the issue
Collections are stuck as a partial object after reloading.

Code snipppets

>>> collection = plex.fetchItem(362)
>>> collection
<Collections:362:test>
>>> collection.isPartialObject()
True
>>> collection.reload()
<Collections:362:test>
>>> collection.isPartialObject()
True

Expected behavior
Collections should be a full object after reloading.

>>> collection = plex.fetchItem(362)
>>> collection
<Collections:362:test>
>>> collection.isPartialObject()
True
>>> collection.reload()
<Collections:362:test>
>>> collection.isPartialObject()
False

Enviroment (please complete the following information):

• Python Version: 3.9.0
• PlexAPI Version: 4.2.0