### 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
_reset_animation_mixers(scene, &anim_backups);
	save_default_environment();
	_save_editor_states(p_file, idx);
	Ref<PackedScene> sdata;
	if (ResourceCache::has(p_file)) {
		
		
		
		sdata = ResourceCache::get_ref(p_file);
		if (sdata.is_valid()) {
			sdata->recreate_state();
		} else {
			sdata.instantiate();
		}
	} else {
		sdata.instantiate();
	}
	Error err = sdata->pack(scene);
	if (err != OK) {
		show_accept(TTR("Couldn't save scene. Likely dependencies (instances or inheritance) couldn't be satisfied."), TTR("OK"));
		return;
	}
	int flg = 0;
	if (EDITOR_GET("filesystem/on_save/compress_binary_resources")) {
		flg |= ResourceSaver::FLAG_COMPRESS;
	}
	flg |= ResourceSaver::FLAG_REPLACE_SUBRESOURCE_PATHS;
	err = ResourceSaver::save(sdata, p_file, flg);
	
	emit_signal(SNAME("scene_saved"), p_file);