C++20 fixes

Fix compilation with gcc13 / c++20 , ROOT 6.28.04 (LCG dev4), fmtlib 10.0.0

• use fmt::runtime where needed (with a hack to still work with fmtlib < 8)
• avoid implicit capture of this in lambdas via [=]
• fix comparison between Gaudi::Property<std::string> and const char*
• hide std::source_location to cling

Closes #266 (closed)

GaudiCommonSvc/src/DataSvc/RecordDataSvc.cpp

@@ -111,7 +111,7 @@ void RecordDataSvc::handle( const Incident& incident ) {
         for ( const auto& i : incidents ) m_incidentSvc->fireIncident( Incident{ i, m_incidentName } );
       }
     }
-  } else if ( incident.type() == m_saveIncidentName ) {
+  } else if ( m_saveIncidentName == incident.type() ) {
     always() << "Saving records not implemented." << endmsg;
   }
 }