[3.5] Remove documentation that mentions 2D navigation baking
[3.5] Remove documentation that mentions 2D navigation baking

Cherrypick mentions 2D navigation mesh baking which does only exist very hidden in Godot 3.5.

ex/godot,ex/godot,ex/godot,ex/godot,ex/godot,ex/godot,ex/godot,ex/godot