Multi-spec packages only need a single .changes file now

Hi, Previously, packages with multiple spec files (e.g. systemd, which has both systemd.spec and systemd-mini.spec) needed a .changes file for each .spec. As the vast majority of changes (e.g. version updates) affect all "flavors", this requirement got dropped and only a single .changes file with the name used for the submit request is needed. It's used for all .spec files during build. References: https://github.com/openSUSE/obs-service-source_validator/pull/88 https://github.com/openSUSE/openSUSE-release-tools/pull/2507 Cheers, Fabian