changelog-v2: mark upgrade action as changelog only
We don't need to recompute the others revlog to add the changelog-v2 feature.
This does not have much effect in practice as the `copies-sdc` upgrade still
triggers the other revlogs. This will be fixed in the next changeset.
Our full contribution guidelines are in our wiki, please see:
https://www.mercurial-scm.org/wiki/ContributingChanges
If you just want a checklist to follow, you can go straight to
https://www.mercurial-scm.org/wiki/ContributingChanges#Submission_checklist
If you can't run the entire testsuite for some reason (it can be
difficult on Windows), please at least run `contrib/check-code.py` on
any files you've modified and run `python contrib/check-commit` on any
commits you've made (for example, `python contrib/check-commit
273ce12ad8f1` will report some style violations on a very old commit).