Caused by {rBd397ecae325}.
Above commit added a new socket, so
`version_geometry_nodes_primitive_uv_maps` was getting the wrong sockect
with `->next`.
Now get the right one with yet another `->next` (might not be ideal, but
searching the right socket with other methods might be overhead?)
Maniphest Tasks: T103837
Differential Revision: https://developer.blender.org/D16994