clanService/paperless: drop psycopg test workaround

The test_stats_connect override was a stopgap for nixpkgs#494510, fixed
upstream in #494536. It forced a rebuild of the whole python package set
(psycopg -> pytest-postgresql -> sqlframe -> narwhals -> scikit-learn),
which broke on a flaky scikit-learn test.

modules/clan/paperless/default.nix

@@ -16,18 +16,6 @@
         ...
       }:
       {
-        nixpkgs.overlays = [
-          (final: prev: {
-            pythonPackagesExtensions = prev.pythonPackagesExtensions ++ [
-              (pyFinal: pyPrev: {
-                psycopg = pyPrev.psycopg.overrideAttrs (old: {
-                  disabledTests = old.disabledTests ++ [ "test_stats_connect" ];
-                });
-              })
-            ];
-          })
-        ];
-
         services.paperless = {
           enable = lib.mkDefault true;
         };