Bug 1559975 - Remove tools/update-packaging from py3 exclude list. r=ahal

Differential Revision: https://phabricator.services.mozilla.com/D35237

--HG--
extra : moz-landing-system : lando

tools/lint/py3.yml

@@ -36,7 +36,6 @@ py3:
         - tools/jprof
         - tools/profiler
         - tools/rb
-        - tools/update-packaging
         - xpcom/idl-parser
     extensions: ['py']
     support-files: