skawarePackages: remove updateScript from man-pages (#415890)

nix-update currently mishandles sourcehut releases and
skawarePackages.buildManPages always sources from sourcehut.

This partially reverts commit 8a9b7acd7390 (skawarePackages: add passthru.updateScript, 2025-05-27).

pkgs/development/skaware-packages/build-skaware-man-pages.nix

···
   lib,
   stdenv,
   fetchFromSourcehut,
-  nix-update-script,
 }:
 
 {
···
   ];
 
   dontBuild = true;
-
-  passthru.updateScript = nix-update-script {
-    extraArgs = [
-      "--override-filename"
-      "pkgs/development/skaware-packages/${lib.removeSuffix "-man-pages" pname}/default.nix"
-    ];
-  };
 
   meta = with lib; {
     inherit description license maintainers;