### 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
for (int i = p_start; i < editor_data.get_edited_scene_count(); i++) {
		if (!editor_data.get_edited_scene_root(i)) {
			continue;
		}
		String scene_filename = editor_data.get_edited_scene_root(i)->get_scene_file_path();
		if (p_valid_filename && scene_filename.is_empty()) {
			continue;
		}
		bool unsaved = EditorUndoRedoManager::get_singleton()->is_history_unsaved(editor_data.get_scene_history_id(i));
		if (unsaved) {
			return i;
		} else {
			for (int j = 0; j < editor_data.get_editor_plugin_count(); j++) {
				if (!editor_data.get_editor_plugin(j)->get_unsaved_status(scene_filename).is_empty()) {
					return i;
				}
			}
		}
	}
	return -1;
}
void EditorNode::_exit_editor(int p_exit_code) {