flake.nix: Update NixOS release to 25.11

mailsystem/postfix.nix

@@ -63,9 +63,6 @@ in {
       hostname = "${cfg.reverseFqdn}";
       networksStyle = "host";
 
-      sslCert = sslCertPath;
-      sslKey = sslKeyPath;
-
       enableSubmissions = true;
 
       mapFiles."virtual_aliases" = aliases_file;
@@ -85,12 +82,17 @@ in {
         cleanup_service_name = "submission-header-cleanup";
       };
 
-      config = {
+      settings.main = {
         mydestination = "";
         recipient_delimiter = "+";
         smtpd_banner = "${cfg.fqdn} ESMTP NO UCE";
         disable_vrfy_command = true;
-        message_size_limit = toString cfg.messageSizeLimit;
+        message_size_limit = cfg.messageSizeLimit;
+
+        smtpd_tls_chain_files = [
+          sslKeyPath
+          sslCertPath
+        ];
 
         virtual_uid_maps = "static:${toString cfg.vmailUID}";
         virtual_gid_maps = "static:${toString cfg.vmailUID}";
@@ -165,7 +167,7 @@ in {
         smtpd_forbid_bare_newline_exclusions = "$mynetworks";
       };
 
-      masterConfig = {
+      settings.master = {
         "lmtp" = {
           # Add headers when delivering, see http://www.postfix.org/smtp.8.html
           # D => Delivered-To, O => X-Original-To, R => Return-Path