Copyright years inconsistent, out of date, and not enforced be CI

[jzulauf-lunarg]

Looking at the Copyright headers some have different ending years for the different copyright holders listed. This differs from practice in other LunarG projects. Also, the autogenerated files (at least) still have prior year's end-date, though all generators have been updated since start of year. Other non-generated files have out of date end years for Copyright. This exists as not copyright check is present in GitHub CI, again differing from other LunarG projects.