Fixes for LCG 104

LCG 104 will have a number of changes including fmtlib 10, new ROOT and C++20 (with gcc13). This require adaptations:

• fixes for fmtlib (compile time checking and explicit formatters), see also gaudi/Gaudi!1462 (merged)
• fix use of std::accumulate (the first argument of the operator must be equivalent to const T&, so T& is not good)
• add missing include of <cstdint>
• fix for implicit == operands swap in C++20, see also gaudi/Gaudi!1466 (merged)
• fix error template-id not allowed for destructor (note that this causes a warning in clang12)
• workarounds for ROOT issues
  • https://github.com/root-project/root/issues/13001
  • https://github.com/root-project/root/issues/12993
  • https://github.com/root-project/root/issues/13019
  • https://github.com/root-project/root/issues/13032
• fix LHCbMath/bit_cast.h for C++20
• fixes for errors reported by Clang 16

It's a bit unrelated, but while at it I fixed a few warnings in Event/Bremsstrahlung.h.

Note: this is part of a pool of related (not interdependent) MRs: Detector!400 (merged), !4143 (merged), Run2Support!46 (merged), Boole!483 (merged), Rec!3449 (merged), Alignment!388 (merged)

See also https://its.cern.ch/jira/projects/LHCBPS/issues/LHCBPS-1912