privacyidea: fix build

ZHF #230712
Failing Hydra build: https://hydra.nixos.org/build/219779719

Another package leaked in a sphinx that's incompatible with the
dependency fixes in here. Removing that solves the issue.

pkgs/applications/misc/privacyidea/default.nix

@@ -167,6 +167,9 @@ let
         sphinxHook = null;
         sphinx-rtd-theme = null;
       }).overridePythonAttrs dropDocOutput;
+      deprecated = (super.deprecated.override {
+        sphinxHook = null;
+      }).overridePythonAttrs dropDocOutput;
     };
   };
 in