Dictionary key tooltips broken

[Repiteo]

Godot version

v4.2.dev.custom_build [6916349]

System information

Windows 11, Forward+ (applicable to all)

Issue description

Hovering over a Dictionary's key will now produce an empty box and throw an error (both pictured below). The old method of setting a key tooltip in editor_properties_array_dict.cpp via prop->set_tooltip_text(cs) is no longer compatable with the new tooltip system

Steps to reproduce

Hover over a dictionary key

Minimal reproduction project

N/A

[jsjtxietian]

The problem is found in that pr's comment: #82051 (comment)

cc @YeldhamDev