package.nix: fix cross for editline

editline's dep on ncurses is a runtime one, so it should be in
buildInputs, not nativeBuildInputs.

CC: https://git.lix.systems/lix-project/lix/issues/527
Change-Id: I631c192a55677b0cc77faa7511986f1fa2205e91

package.nix

@@ -22,7 +22,6 @@
   doxygen,
   editline-lix ? __forDefaults.editline-lix,
   editline,
-  fetchpatch,
   git,
   gtest,
   jq,
@@ -100,7 +99,7 @@
         (lib.enableFeature (ncurses != null) "termcap")
       ];
 
-      nativeBuildInputs = (prev.nativeBuildInputs or [ ]) ++ [ ncurses ];
+      buildInputs = (prev.buildInputs or [ ]) ++ [ ncurses ];
     });
 
     build-release-notes = callPackage ./maintainers/build-release-notes.nix { };