fix the date on v7.2.1 release

Two issues:
 - the intended date was March 30th 2023, but the year wasn't updated
 - the March 30th date is when the VERSION file was updated, but the
   actual tag was April 5th 2023, so used that date instead.

Reported-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Michael Roth <michael.roth@amd.com>