support/download: change format of archives generated from svn

support/download: change format of archives generated from svn

Like we recently did for git, switch the archives generated from
subversion to be reproducible whatever the tar version.

We have no in-tree users of the svn backend which also has hashes,
so no hash to update.

Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
Cc: Heiko Thiery <heiko.thiery@gmail.com>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Vincent Fazio <vfazio@xes-inc.com>
Reviewed-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Reviewed-by: Vincent Fazio <vfazio@xes-inc.com>