libsForQt5: change comment

It wouldn't work that way, idk why I thought it would.

pkgs/top-level/qt5-packages.nix

@@ -259,8 +259,9 @@ in (noExtraAttrs (kdeFrameworks // plasmaMobileGear // plasma5 // plasma5.thirdP
 
   yuview = callPackage ../applications/video/yuview { };
 }) // lib.optionalAttrs pkgs.config.allowAliases {
-  # remove after 23.11 branch-off and backport removal to 23.11
-  # 23.11 will have a warning for this in `makeScope` itself
-  overrideScope' = lib.warn "libsForQt5 now uses makeScopeWithSplicing which does not have \"overrideScope'\", use \"overrideScope\"." self.overrideScope;
+  # Convert to a throw on 03-01-2023 and backport the change.
+  # Warnings show up in various cli tool outputs, throws do not.
+  # Remove completely before 24.05
+  overrideScope' = lib.warnIf (lib.isInOldestRelease 2311) "libsForQt5 now uses makeScopeWithSplicing which does not have \"overrideScope'\", use \"overrideScope\"." self.overrideScope;
 }));
 }