hub: make patch urls reproducible

pkgs/applications/version-management/hub/default.nix

···
 
   patches = [
     # Fix `fish` completions
+    # https://github.com/github/hub/pull/3036
     (fetchpatch {
-      url = "https://github.com/github/hub/pull/3036.patch";
+      url = "https://github.com/github/hub/commit/439b7699e79471fc789929bcdea2f30bd719963e.patch";
       hash = "sha256-pR/OkGa2ICR4n1pLNx8E2UTtLeDwFtXxeeTB94KFjC4=";
     })
     # Fix `bash` completions
+    # https://github.com/github/hub/pull/2948
     (fetchpatch {
-      url = "https://github.com/github/hub/pull/2948.patch";
+      url = "https://github.com/github/hub/commit/64b291006f208fc7db1d5be96ff7db5535f1d853.patch";
       hash = "sha256-jGFFIvSKEIpTQY0Wz63cqciUk25MzPHv5Z1ox8l7wmo=";
     })
   ];