Hide LPE tool in defoult preference

Steps to reproduce:

• open Inkscape (with new preference)
• look at toolbar
• see LPE tool

What happened?

-LPE tool is there

What should have happened?

-LPE tool is broken experimental feature that should be hidden form final relese

Inkscape Version and Operating System:

• Inkscape Version: 1.4b
• Operating System: ...
• Operating System version: ...