fix(nix): Temporarily disable linking with systemd

Fixes:

error: The Haskell package set does not contain the package: lobemo-scribe-systemd (build
dependency).  If you are using Stackage, make sure that you are using a snapshot that
contains the package. Otherwise you may need to update the Hackage snapshot you are using,
usually by updating haskell.nix.

Author: sgillespie

flake.nix

@@ -245,6 +245,20 @@
                   packages.cardano-chain-gen.components.tests.cardano-chain-gen =
                     postgresTest;
                 })
+
+              ({ lib, pkgs, ... }: {
+                # TODO[sgillespie]: The following line is currently required to avoid
+                # the following error:
+                #
+                #     error: The Haskell package set does not contain the package:
+                #     lobemo-scribe-systemd (build dependency).  If you are using Stackage,
+                #     make sure that you are using a snapshot that contains the
+                #     package. Otherwise you may need to update the Hackage snapshot you are
+                #     using, usually by updating haskell.nix.
+                #
+                # This started happening here: https://github.com/input-output-hk/hackage.nix/commit/958f69d793847b532874a66201a491423f2ec551
+                packages.cardano-node.flags.systemd = lib.mkForce false;
+              })
             ];
           })).appendOverlays [
             # Collect local package `exe`s