Fix typos with codespell

Using codespell 2.0.0.

Method:
```
$ cat > ../godot-word-whitelist.txt << EOF
ang
curvelinear
dof
doubleclick
fave
findn
GIRD
leapyear
lod
merchantibility
nd
numer
ois
ony
que
seeked
synching
te
uint
unselect
webp
EOF

$ codespell -w -q 3 -I ../godot-word-whitelist.txt --skip="./thirdparty,*.po"
$ git diff // undo unwanted changes
```

editor/editor_data.h

@@ -167,7 +167,7 @@ public:
 	EditorPlugin *get_editor_plugin(int p_idx);
 
 	UndoRedo &get_undo_redo();
-	void add_undo_redo_inspector_hook_callback(Callable p_callable); // Callbacks shoud have 4 args: (Object* undo_redo, Object *modified_object, String property, Varian new_value)
+	void add_undo_redo_inspector_hook_callback(Callable p_callable); // Callbacks should have 4 args: (Object* undo_redo, Object *modified_object, String property, Variant new_value)
 	void remove_undo_redo_inspector_hook_callback(Callable p_callable);
 	const Vector<Callable> get_undo_redo_inspector_hook_callback();