Merge pull request #122060 from Ma27/hydra-maintainer-fix

maintainers/check-hydra-by-maintainer: use `pkgs.hydra-check` from package set itself

maintainers/scripts/check-hydra-by-maintainer.nix

···
 in
 pkgs.stdenv.mkDerivation {
   name = "nixpkgs-update-script";
+  buildInputs = [ pkgs.hydra-check ];
   buildCommand = ''
     echo ""
     echo "----------------------------------------------------------------"