Disable functionality reported in T60766 & only partially worked.
This could be used if the key-map was added after Blender started
as a way to customize modal key-maps, however it didn't work with
the add-on enabled on startup.
Add-on key-maps are intended to extend existing key-maps
so they can call the add-on, not as a way to change modal key-maps
for Blender's built-in functionality.
Disable this since it's not needed as add-ons
can't yet define modal key-maps.
e8dd96516c