scdaq: Bump base image CS7 -> Ubi8 (RHEL8)
CS Stream 7 support is deprecated by CERN.
This MR bumps our SCDAQ image to Ubi8, the minimal distribution for RHEL8, as the latter is unavailable for docker images in its license with CERN.
The packages `tbb-devel` and `boost-devel` required some massaging, i.e.:
- manually installing the EPEL 8 (extra packages) repository for `boost`, which provides versions 1.78, 1.69. This is preferable because dependency resolution is nontrivial for
boost
packages, which EPEL can handle automatically. - manually installing
tbb
, thentbb-devel
, (Intel, 2018 version), directly from RPM packages.