Blender Git Loki

Fix T62463: unable to select anim channel for unselected node

Remove the code that synchronises selection state of shader node animation
channels. This code is only used in a few cases where selection of these
animation channels is changed, and then potentially does the wrong thing
and disallows selection of animation channels altogether.

This removal is meant to be a temporary situation, to unblock animation
channel selection. See T74159 for the overall effort to improve selection
sync.