systemd: Patch journald's Audit setting

https://github.com/systemd/systemd/pull/39069

nixos/modules/system/boot/systemd/journald.nix

@@ -79,8 +79,11 @@ in
     };
 
     services.journald.audit = lib.mkOption {
-      default = null;
-      type = lib.types.nullOr lib.types.bool;
+      default = "keep";
+      type = lib.types.oneOf [
+        lib.types.bool
+        (lib.types.enum [ "keep" ])
+      ];
       description = ''
         If enabled systemd-journald will turn on auditing on start-up.
         If disabled it will turn it off. If unset it will neither enable nor disable it, leaving the previous state unchanged.

pkgs/os-specific/linux/systemd/default.nix

@@ -230,6 +230,12 @@ stdenv.mkDerivation (finalAttrs: {
       hash = "sha256-DO6q17mE2U8iLezMYt4PX5Ror20N1gCrUbXeQmrW1is=";
     })
 
+    # https://github.com/systemd/systemd/pull/39069
+    (fetchpatch {
+      url = "https://github.com/systemd/systemd/commit/b5fdfedf729712b9824a5cb457a07d5699d2946c.patch";
+      hash = "sha256-0SvAn9Dl4z80PRIvDbIVIjKp5DsT/IUoHa5IiH1HHFY=";
+    })
+
     ./0001-Start-device-units-for-uninitialised-encrypted-devic.patch
     ./0002-Don-t-try-to-unmount-nix-or-nix-store.patch
     ./0003-Fix-NixOS-containers.patch