flatdeb-builder: Use the packaged flatdeb
This also allows us to easily get the changes in v2021-updates.
https://phabricator.apertis.org/T8507
Signed-off-by: Ryan Gonzalez ryan.gonzalez@collabora.com
It seems like this being left here was an accident? I'm guessing I should do this to the v2022 and v2023 as well.