Fix: PostgreSQL APT repository configuration + repository priority

[CelestineSauvage]

Fix PostgreSQL APT repository configuration

Description

This PR fixes two issues in the PostgreSQL APT repository configuration:

Changes

• Replace deprecated apt-key usage

  • Replace apt-key with a dedicated keyring.
  • Configure the PGDG repository using signed-by.

• Fix package priority and dependency resolution

  • Add APT pinning to ensure PostgreSQL-related packages are preferred from the PGDG repository.

  • Prevent APT from mixing packages from the Ubuntu repository and PGDG when resolving dependencies.

  • This fixes installation failures such as:

    The following packages have unmet dependencies:
     libhdf4-alt-dev : Conflicts: libhdf4-dev but 4.2.16-4build1 is to be installed
     libhdf4-dev : Conflicts: libhdf4-alt-dev but 4.2.16-4build1 is to be installed
    

  • PostgreSQL packages (postgresql-*, postgresql-client-*, libpq5, libpq-dev) are given a higher priority from PGDG, while other packages from the PGDG repository keep a lower priority.

Conclusion

Use the recommended APT key management approach and ensure consistent package selection during dependency resolution, avoiding conflicts caused by packages being selected from different repositories.