This was overlooked, as it seems there's no way for these strings to be
translated currently. Generally it's not that clear whether `N_` or
`TIP_` should be used in this case, but `TIP_` seems more consistent.
To avoid the cost of the translation lookup when the UI text isn't
necessary, we could allow the disabled hint argument to be optional.
Differential Revision: https://developer.blender.org/D13141
