When doing partial reloads of asset libraries (only reload assets from
the current file, e.g. after undo re-allocated ID pointers), we'd end up
with assets that don't have their asset data read correctly. It would
execute a branch that didn't set the asset library object necessary to
create and store asset representations.
Steps to reproduce were:
* Open .blend file with geometry node assets in there
* In a geometry node editor, press Shift+A to open the add menu
* Cancel
* Move a node
* Undo
* Press Shift+A again
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