stdenv setup: Always use both propagated files

This continues #23374, which always kept around both attributes, by
always including both propagated files: `propgated-native-build-inputs`
and `propagated-build-inputs`. `nativePkgs` and `crossPkgs` are still
defined as before, however, so this change should only barely
observable.

This is an incremental step to fully keeping the dependencies separate
in all cases.

pkgs/development/libraries/kde-frameworks/default.nix

@@ -56,11 +56,7 @@ let
                     # Propagate $dev so that this setup hook is propagated
                     # But only if there is a separate $dev output
                     if [ "$outputDev" != out ]; then
-                        if [ -n "$crossConfig" ]; then
-                          propagatedBuildInputs="$propagatedBuildInputs @dev@"
-                        else
-                          propagatedNativeBuildInputs="$propagatedNativeBuildInputs @dev@"
-                        fi
+                        propagatedBuildInputs="$propagatedBuildInputs @dev@"
                     fi
                 fi
               '';