The simulator has advanced considerably, and it is seeing lots of active
development, so make it a required part of KiCad. Additionally, the
build without the simulator has actually been broken for a while, so no
one clearly is building without ngspice right now.
Since Linux now uses a symlink for the pcbnew python shared library, we
need to ensure the target of that symlink is also in the artifact zip.
So include the pcbnew kiface in the artifacts list.
* Don't run the Ubuntu job on schedules
* Fix Coverity job by being explicit it is for schedules only
* Separate the caches for the Ubuntu and Fedora jobs
Eventually we probably want to just pick one target for it,
but for now this means we can get faster test results as long
as we have a faster Ubuntu runner.