Disabling 'node_placement_prediction' disables node placement sound

Minetest version

5.6.0

Summary

Adding node_placement_prediction = "", to a node definition prevents the node placement sound from being played.

Steps to reproduce

Add node_placement_prediction = "", to a node definition.

Additional info

First encountered when I disabled the prediction on stairs, since the flickering caused by the prediction immediately followed by the actual rotation is annoying, but I have also tested it with simple dirt to the same result.