Source packages referenced by Built-Using missing in noble

[Thomas Weißschuh]

The package grub-common 2.12-1ubuntu7 in Ubuntu noble (amd64) specifies
`Built-Using: lzo2 (= 2.10-2build3)`.
However the lzo2 2.10-2build3 source package is not available in the Ubuntu noble repositories.
Only the current version 2.10-2build4 is. (The same issue also affects other packages)
The source packages should be available in the repository as long as they are referenced to satisfy license requirements.
It seems the current handling of "Built-Using" in ubuntu-archive-tools does not handle package versions at all.

Debian policy 7.8: Additional source packages used to build the binary - Built-Using

    This causes the Debian archive to retain the versions of the source packages that were actually incorporated. In particular, if the versions of the incorporated parts are updated but the incorporating binary package is not rebuilt, the older versions of the incorporated parts will remain in the archive in order to satisfy the license.

Background: https://github.com/Linutronix/elbe/issues/430