### 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
ERR_FAIL_NULL_V_MSG(p_object, nullptr, "Object cannot be null.");
	Ref<Script> scr = p_object->get_script();
	if (scr.is_null() && p_object->is_class("Script")) {
		scr = p_object;
	}
	return _get_class_or_script_icon(p_object->get_class(), scr, p_fallback);
}
Ref<Texture2D> EditorNode::get_class_icon(const String &p_class, const String &p_fallback) {
	ERR_FAIL_COND_V_MSG(p_class.is_empty(), nullptr, "Class name cannot be empty.");
	Ref<Script> scr;
	if (ScriptServer::is_global_class(p_class)) {
		scr = EditorNode::get_editor_data().script_class_load_script(p_class);
	}
	return _get_class_or_script_icon(p_class, scr, p_fallback, true);
}
bool EditorNode::is_object_of_custom_type(const Object *p_object, const StringName &p_class) {