[v2024] Backport sanity checks added to v2025dev2

We have added a number of sanity checks to the CI in v2025dev2, so that the Debian metadata is checked to ensure it's been updated and we aren't building kernel variants that we don't need. Backport these changes to v2024 so we have the same checks here too.

Signed-off-by: Martyn Welch martyn.welch@collabora.com