Fix config to avoid early exit

This migrates to DumpGeo the fix introduced for VP1 in !71773 (merged) by @emoyse.

The MR fixes the early exit of DumpGeo observed starting from the r21 nightly build (21 May 2024).

DetectorDescription/GeoModel/DumpGeo/python/DumpGeoConfig.py

@@ -175,7 +175,7 @@ if __name__=="__main__":
 
     args = flags.fillFromArgs(parser=parser)
 
-    if 'help' in args:
+    if args.help:
         # No point doing more here, since we just want to print the help.
         sys.exit()