Switched to C++20

CMakeLists.txt

...orPlugins/FSLExamplePrimaryGeneratorPlugin/CMakeLists.txt

...ticFieldPlugins/UniformMagneticFieldPlugin/CMakeLists.txt

.../PhysicsListPlugins/FSLTestPhysListPlugins/CMakeLists.txt

...Examples/SensitiveDetectorPlugins/SDPlugin/CMakeLists.txt

...es/UserActionPlugins/DummyUserActionPlugin/CMakeLists.txt

FullSimLight/Plugins/HitsPlugin/CMakeLists.txt

FullSimLight/Plugins/TracksPlugin/CMakeLists.txt

GeoModelExamples/GeoActions/CMakeLists.txt

GeoModelExamples/GeoActionsCountNodes/CMakeLists.txt

GeoModelExamples/GeoFullPhysVol/CMakeLists.txt

GeoModelExamples/GeoShapeExamples/CMakeLists.txt

GeoModelExamples/GeoShiftUnion/CMakeLists.txt

GeoModelExamples/GeoTessellatedSolidExamples/CMakeLists.txt

GeoModelExamples/HelloDummyMaterial/CMakeLists.txt

GeoModelExamples/HelloGeo/CMakeLists.txt

GeoModelExamples/HelloGeoRead/CMakeLists.txt

GeoModelExamples/HelloGeoReadNodeAction/CMakeLists.txt

GeoModelExamples/HelloGeoWrite/CMakeLists.txt

GeoModelExamples/HelloGeoWriteReadWrite/CMakeLists.txt