### 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
Timer *screenshot_timer = nullptr;
	uint64_t started_timestamp = 0;
	RichTextLabel *load_errors = nullptr;
	AcceptDialog *load_error_dialog = nullptr;
	RichTextLabel *execute_outputs = nullptr;
	AcceptDialog *execute_output_dialog = nullptr;
	Ref<Theme> theme;
	PopupMenu *recent_scenes = nullptr;
	String _recent_scene;
	List<String> previous_scenes;
	String defer_load_scene;
	Node *_last_instantiated_scene = nullptr;
	ConfirmationDialog *confirmation = nullptr;
	ConfirmationDialog *save_confirmation = nullptr;
	ConfirmationDialog *import_confirmation = nullptr;
	ConfirmationDialog *pick_main_scene = nullptr;
	Button *select_current_scene_button = nullptr;
	AcceptDialog *accept = nullptr;
	AcceptDialog *save_accept = nullptr;
	EditorAbout *about = nullptr;
	AcceptDialog *warning = nullptr;
	EditorPlugin *plugin_to_save = nullptr;
	int overridden_default_layout = -1;
	Ref<ConfigFile> default_layout;
	PopupMenu *editor_layouts = nullptr;
	EditorLayoutsDialog *layout_dialog = nullptr;
	ConfirmationDialog *gradle_build_manage_templates = nullptr;
	ConfirmationDialog *install_android_build_template = nullptr;
	ConfirmationDialog *remove_android_build_template = nullptr;
	PopupMenu *vcs_actions_menu = nullptr;