services/nomad/build/buildbot: sort packages before printing

this should fix ordering issues with split logs

Author: classabbyamp

services/nomad/build/buildbot.cfg

@@ -286,7 +286,7 @@ factory.addStep(ShellCommandWithChanges(
 ))
 
 factory.addStep(steps.SetPropertyFromCommand(
-    command=['make', 'print_pkgs'],
+    command=['make', 'sort', 'print_pkgs'],
     property='packages',
     name='get_packages',
     description='collecting packages to build',