Add soversion option for ROOT in centos7 bundles
As discussed in https://git.km3net.de/working_groups/comp_soft/-/issues/150 the missing soversion
option results in a 10-times slower performance when e.g. using Minuit2.
This MR sets the soversion
flag for the ROOT compilation.
All singularity images which were built using these centos7 bundle base images should be rebuilt.