It always causes linker errors

(cherry picked from commit d824fe1a)

cobertura was removed in gitlab 15.0 --> https://git.rz.tu-bs.de/help/ci/yaml/artifacts_reports.md

https://github.com/gcovr/gcovr/issues/577

Adds python dependency to vf dockerfile and removes the redudant docker file, as singularity is not need anymore here. Adjust the CI.

Run python build and tests only when scheduled due to long build times and a not working reuse of the cache.

peters authored 3 years ago and Sören Peters committed 3 years ago

Add build cache cmake function. Use ccache if available. Therefore removed ccache presets and update the ci script. Prevent insource builds. Add compiler warnings target, which is not in use so far.