fix: nixos test for pg_net

We are still using the nixos module to install postgresql with the
pg_net extension. That module requires the package to define the
`withJIT` and `withoutJIT` attributes.

The previous implementation did not return the correct package for those
attributes, which caused the test to fail.

Author: jfroche

nix/ext/tests/pg_net.nix

@@ -21,12 +21,11 @@ let
           inherit (postgresql)
             version
             psqlSchema
-            withJIT
-            withoutJIT
             ;
           lib = pkg;
           withPackages = _: pkg;
           installedExtensions = [ (installedExtension majorVersion) ];
+          withoutJIT = pkg;
         };
         nativeBuildInputs = [ pkgs.makeWrapper ];
         pathsToLink = [