D5619: tests: sort py3 whitelist to make test-check-code.t happy

[pulkit (Pulkit Goyal)]

pulkit added a comment.


  This one does not apply anymore on tip of default branch.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D5619

To: martinvonz, pulkit, #hg-reviewers
Cc: mercurial-devel