Consider disabled packages as success even if they failed to build

Scenario:

1. cross-toolchain-base branched/mirrored on OBS
2. for some reason, it gets enabled on all architecture, as that's the default
3. it fails to build on armv7hl as expected
4. the pipeline fails
5. someone notices and disables armv7hl on the package on OBS
6. the job is restarted to reflect that it is disabled

Unfortunately right now the pipeline first checks the result in the build history first and checks for disabled packages only later, so it only works for packages that have never been built.

Make it check if the package is disabled as a first thing and bail out early if that's the case.