Fix Continuous Integration

The external flesnet requires at least CMake 3.14.0. Check already in our CMakeLists.txt if this version is available, otherwise the test is done when building flesnet and the error is hidden in some log file. Use CMake from the FairSoft installation on the CI runner (lxir116 )where the CMake version is to old.

added BugFix Build System labels

requested review from @f.uhlig

assigned to @f.uhlig

Dear @f.uhlig, @v.friese, @p.-a.loizeau,

you have been identified as code owner of at least one file which was changed with this merge request.

Please check the changes and approve them or request changes.

added CodeOwners label

merged