Add restartIfChanged option to lidarr-mb-gap service configuration

- Introduced the `restartIfChanged` option set to false in the lidarr-mb-gap NixOS module to control service restart behavior.
- This change enhances service management by preventing unnecessary restarts when configuration changes occur without affecting the service's operational state.

nixos/lidarr-mb-gap.nix

@@ -134,6 +134,7 @@ in
       description = "Generate Lidarr MusicBrainz Gap Report";
       after = [ "network.target" ];
       wantedBy = [ "multi-user.target" ];
+      restartIfChanged = false;
 
       serviceConfig = {
         Type = "oneshot";