apache-guacamole: require Debian 13 (#18094)

freerdp3-dev exists from Trixie on; a Debian 12 override failed at the
dependency install.

install/apache-guacamole-install.sh

@@ -12,6 +12,11 @@ setting_up_container
 network_check
 update_os
 
+if is_debian && [[ "$(get_os_version_major)" -lt 13 ]]; then
+  msg_error "Apache Guacamole needs Debian 13: freerdp3-dev is not available on Debian 12."
+  exit 238
+fi
+
 msg_info "Installing Dependencies"
 $STD apt install -y \
   build-essential \