Adapt test certificates generation

Adapt test certificates generation

Bug-Debian: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1078640
Forwarded: not-needed
Last-Update: 2025-07-15

Adapt the test certificates generation process to Debian. For that, we extend
the validity of the certificates to 11 years to try to cover the Debian support
(and hopefully the LTS/eLTS) window as long as a build is performed 1 year
before a release. We also require certificate_authority from the installed
package so we can generate this certificates without external packages.
Last-Update: 2025-07-15

Gbp-Pq: Name 0019-adapt-test-certs-generation.patch