Make generated copyright year be "now"

Make generated copyright year be "now"

Always use the current year in generating output files, rather than
trying to base is on the modtime of the script or input, as that can
vary depending on the ability of the local OS to keep those accurate.

Fixes #10744

Reviewed-by: Shane Lontis <shane.lontis@oracle.com>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/10776)