Cleanup of script for convertation to ostree

Removed unneeded but included dependencies.

Signed-off-by: Denis Pynkin <denis.pynkin@collabora.com>
Reviewed-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Reviewed-by: Héctor Orón Martínez <hector.oron@collabora.co.uk>
Differential Revision: https://phabricator.apertis.org/D7275