This was caused by 87c011f8bb. The drawing code for the input nodes was moved
into a new `custom_draw_fn` callback on the socket declaration. This was not
taken into account when drawing the sidebar yet, which is an oversight and was
not an intentional change.
This fix applies to all the nodes that use the new custom draw function.
Pull Request: https://projects.blender.org/blender/blender/pulls/141872