update the date in the added file header

src/mol-model-formats/structure/pdb/header.ts

 /**
- * Copyright (c) 2019-2021 mol* contributors, licensed under MIT, See LICENSE file for more info.
+ * Copyright (c) 2023 mol* contributors, licensed under MIT, See LICENSE file for more info.
  *
  * @author Yana Rose <yana.v.rose@gmail.com>
  */