Update Rspamd to 3.11.0 and enable SMTPUTF8 for outgoing mail (#6216)

* Update Rspamd to 3.11

* Enable SMTPUTF8 and hide it from SMTPD greeting

* Update options.inc

* compose: increased rspamd tag

data/conf/rspamd/local.d/options.inc

@@ -3,6 +3,7 @@ dns {
 }
 map_watch_interval = 30s;
 task_timeout = 30s;
+enable_mime_utf = true;
 disable_monitoring = true;
 # In case a task times out (like DNS lookup), soft reject the message
 # instead of silently accepting the message without further processing.