base/borg-config: use zstd compression for borgmatic configs

base/borg-config.nix

@@ -135,6 +135,8 @@ in
           ];
           encryption_passcommand = ''cat ${config.sops.secrets."borgmatic_pass/local".path}'';
 
+          compression = "zstd";
+
           keep_daily = 7;
           keep_weekly = 4;
           keep_monthly = 12;
@@ -170,6 +172,8 @@ in
 
           unknown_unencrypted_repo_access_is_ok = false;
 
+          compression = "zstd";
+
           ssh_command = sshCommand;
 
           mariadb_databases = cfg.mariadbDatabases;