grimblast: add passthru.updateScript

pkgs/by-name/gr/grimblast/package.nix

@@ -13,6 +13,7 @@
   slurp,
   wl-clipboard,
   bash,
+  nix-update-script,
 }:
 
 stdenvNoCC.mkDerivation (finalAttrs: {
@@ -57,6 +58,8 @@ stdenvNoCC.mkDerivation (finalAttrs: {
       }"
   '';
 
+  passthru.updateScript = nix-update-script { extraArgs = [ "--version=branch" ]; };
+
   meta = with lib; {
     description = "Helper for screenshots within Hyprland, based on grimshot";
     license = licenses.mit;