package: drop unversioned hash files

package: drop unversioned hash files

The download infra now knows to look for per-version hash files, so we
can now drop the unversioned hash files.

Instead of removing them, add a comment that redirects the developper to
update the per-version hash files instead (so they do not re-add a
unversioned one in the future).

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Gaël Portay <gael.portay@savoirfairelinux.com>
Cc: Peter Seiderer <ps.report@gmx.net>
Cc: Julien Corjon <corjon.j@ecagroup.com>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Arnout Vandecappelle <arnout@mind.be>
Cc: Luca Ceresoli <luca@lucaceresoli.net>
Cc: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>