Add libnotify_actor

flake.nix

@@ -37,6 +37,7 @@
               configureFlags = configureFlags ++ [ "--enable-debug" ];
             });
           in mkShell { packages = [ libnl' pkg-config ]; };
+          libnotify_actor = mkShell { packages = [ libnotify pkg-config ]; };
           nix_actor = mkShell { packages = [ boost nix pkg-config ]; };
           zua = mkShell { packages = [ fontconfig pkg-config SDL2 ]; };
         }) nixpkgs.legacyPackages;