Explicitly fix the version of LHCb required
Update cmake/Run2SupportDependencies.cmake
Following discussion with @clemenci this will ensure that cmake issues an error when building Run2Support if at least LHCb v53r9p3 is not found. Since this is needed to pick up a MR in LHCb needed by Gauss to run when data type is set to 2022/2023 is it actually better to know it ahead of time...