EditorSettings: Rename invert_y-axis to invert_y_axis for consistency

No other option uses a dash in its identifier.

editor/plugins/spatial_editor_plugin.cpp

@@ -1901,7 +1901,7 @@ void SpatialEditorViewport::_nav_orbit(Ref<InputEventWithModifiers> p_event, con
 
 	real_t degrees_per_pixel = EditorSettings::get_singleton()->get("editors/3d/navigation_feel/orbit_sensitivity");
 	real_t radians_per_pixel = Math::deg2rad(degrees_per_pixel);
-	bool invert_y_axis = EditorSettings::get_singleton()->get("editors/3d/navigation/invert_y-axis");
+	bool invert_y_axis = EditorSettings::get_singleton()->get("editors/3d/navigation/invert_y_axis");
 
 	if (invert_y_axis) {
 		cursor.x_rot -= p_relative.y * radians_per_pixel;
@@ -1926,7 +1926,7 @@ void SpatialEditorViewport::_nav_look(Ref<InputEventWithModifiers> p_event, cons
 
 	real_t degrees_per_pixel = EditorSettings::get_singleton()->get("editors/3d/navigation_feel/orbit_sensitivity");
 	real_t radians_per_pixel = Math::deg2rad(degrees_per_pixel);
-	bool invert_y_axis = EditorSettings::get_singleton()->get("editors/3d/navigation/invert_y-axis");
+	bool invert_y_axis = EditorSettings::get_singleton()->get("editors/3d/navigation/invert_y_axis");
 
 	// Note: do NOT assume the camera has the "current" transform, because it is interpolated and may have "lag".
 	Transform prev_camera_transform = to_camera_transform(cursor);