Allow the ability to exclude errata packages

[javihernandez]

Sometimes, AlmaLinux doesn't release some packages, such as openssl-fips-provider.
When an openssl errata is processed, openssl-fips-provider packages are automatically added, and since these packages are not in AlmaLinux, the errata release fails.

As of now, we delete those errata packages manually, but it would be great to put a mechanism in place that is able to skip those errata packages, either automatically or manually using the UI.