Store build source package with pristine-lfs

Once CI does a release and creates a new tag store the source package in pristine-lfs. This allows to simply pick up the exact same source package again when doing again a release of an already-tagged version.

Main use-case is release a package first for e.g. a development version and then backporting it into the currrent stable apertis version

Signed-off-by: Sjoerd Simons sjoerd.simons@collabora.co.uk