cmGlobalXCodeGenerator: disable C++ module scanning for force-lang files

Source/cmGlobalXCodeGenerator.cxx

@@ -1697,6 +1697,7 @@ void cmGlobalXCodeGenerator::ForceLinkerLanguage(cmGeneratorTarget* gtgt)
   }
   if (cmSourceFile* sf = mf->GetOrCreateSource(fname)) {
     sf->SetProperty("LANGUAGE", llang);
+    sf->SetProperty("CXX_SCAN_FOR_MODULES", "0");
     gtgt->AddSource(fname);
   }
 }