### Godot version

master

### System information

Godot v4.2.beta (0ea75d77c) - Windows 10.0.22621 - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 2070 (NVIDIA; 31.0.15.3598) - Intel(R) Core(TM) i7-10750H CPU @ 2.60GHz (12 Threads)

### Issue description

When any of the Import, Filesystem, Node, or History docks are floating, changing an editor feature crashes the engine.
Changing any setting or selecting a different profile triggers it.

This is because `EditorNode::_feature_profile_changed` assumes the docks are in a `TabContainer`, and if they are floating they aren't in one.


### Steps to reproduce

Make any of these docks floating: Import, Filesystem, Node, or History
Open Editor Features (Editor -> Manage Editor Features...)
Make a profile (if you have none) or change a setting on the existing profile

### Minimal reproduction project

n/a
return ext_icon;
	}
	
	
	const EditorData::CustomType *ctype = ed.get_custom_type_by_name(p_class);
	if (ctype && ctype->icon.is_valid()) {
		return ctype->icon;
	}
	
	
	if (theme.is_valid()) {
		if (theme->has_icon(p_class, EditorStringName(EditorIcons))) {
			return theme->get_icon(p_class, EditorStringName(EditorIcons));
		}
		if (!p_fallback.is_empty() && theme->has_icon(p_fallback, EditorStringName(EditorIcons))) {
			return theme->get_icon(p_fallback, EditorStringName(EditorIcons));
		}
		
		if (ClassDB::class_exists(p_class)) {
			bool instantiable = !ClassDB::is_virtual(p_class) && ClassDB::can_instantiate(p_class);
			if (ClassDB::is_parent_class(p_class, SNAME("Node"))) {
				return theme->get_icon(instantiable ? "Node" : "NodeDisabled", EditorStringName(EditorIcons));
			} else {
				return theme->get_icon(instantiable ? "Object" : "ObjectDisabled", EditorStringName(EditorIcons));
			}
		}
	}
	return nullptr;
}
Ref<Texture2D> EditorNode::get_object_icon(const Object *p_object, const String &p_fallback) {