sourcehut: mark as broken

There were several custom python dependencies broken. I decided to
modify the `sourcehut` expression as it wouldn't even evaluate without
nodejs-11_x I didn't manage to get it building.

(cherry picked from commit 594378ceea)

pkgs/applications/version-management/sourcehut/core.nix

@@ -75,6 +75,7 @@ buildPythonPackage rec {
     homepage = https://git.sr.ht/~sircmpwn/srht;
     description = "Core modules for sr.ht";
     license = licenses.bsd3;
+    broken = true;
     maintainers = with maintainers; [ eadwu ];
   };
 }