component/postfix: Add support for Linux 6.

  INFO (echo "# Do not edit -- this file documents how Postfix was built for your machine."; /bin/sh makedefs) >makedefs.tmp
  INFO ATTENTION:
  INFO ATTENTION: Unknown system type: Linux 6.1.6-arch1-3
  INFO ATTENTION:
  INFO make: *** [Makefile.in:33: Makefiles] Error 1
  INFO make: *** [Makefile:22: makefiles] Error 2
10 jobs for master in 0 seconds
Status Job ID Name Coverage
  External
passed Cloudooo.UnitTest-Master

00:09:34

passed ERP5.StandaloneDeploymentScriptTest-Debian.Buster

00:28:02

passed ERP5.StandaloneDeploymentScriptTest-Debian.Buster.Master

06:39:17

passed SlapOS-Master.StandaloneDeploymentScriptTest-Debian.Buster

00:28:35

passed SlapOS.Eggs.UnitTest-Master.Python2

00:14:12

passed SlapOS.Eggs.UnitTest-Master.Python3

00:13:59

passed SlapOS.KVM.ResilienceTest-Master

00:20:41

failed SlapOS.SoftwareReleases.IntegrationTest-Master

05:49:57

passed SlapOS.Theia.ResilienceTest-Master

09:39:24

passed Wendelin.StandaloneDeploymentScriptTest-Debian.Buster

00:23:28