valgrind: Add perl as a native build input

The changes in #67548 broke cross-compilation not for valgrind, but for
software relying on valgrind at build-time.

pkgs/development/tools/analysis/valgrind/default.nix

@@ -16,6 +16,9 @@ stdenv.mkDerivation rec {
   # Perl is needed for `callgrind_{annotate,control}'.
   buildInputs = [ gdb perl ]  ++ stdenv.lib.optionals (stdenv.isDarwin) [ bootstrap_cmds xnu ];
 
+  # Perl is also a native build input.
+  nativeBuildInputs = [ perl ];
+
   enableParallelBuilding = true;
   separateDebugInfo = stdenv.isLinux;