It is a little noisy to see patches only to update the copyright year lines.
Can we please add a pre-push hook to warn the authors about that?

Facts:
- 3711 issues appears when I search in the bug system using keyword 'copyright' (not all are just to update copyright years)
- patches can be located by using the following command, (not too many for jdk16)
`git log jdk-16+0..jdk-16-ga --oneline --grep=copyright`