changelog: Switch to using lerna-changelog

[dcyriller]

Description

This PR implements the item move to lerna changelog from custom solution referenced in #6103

The goal is to simplify / standardize the changelog generation around an external solution. It allows to remove some infrastructure code.

The RELEASE notes are taken and adapted from ember-template-lint.

Github UI Labels

I configured lerna-changelog to read ember-data labels: changelog:*. This configuration would require making two changes to ember-data Github labels: you would have to create a changelog:breaking label for breaking changes and remove the changelog:security label (it has been used only once for a dependabot dep ugprade).

Giving it a try

Checkout the branch locally, install deps and run: yarn lerna-changelog --from=3.13.3.

Note: you might have to add a token to fetch from Github API: https://github.com/lerna/lerna-changelog#github-token

Caveat

It would genereate a CHANGELOG based on Github labels only, meaning that it would not reference any commit anymore. Previously, the changelog script used to also generate CHANGELOG entries based on commit prefixes ([FEAT] / [CHORE] for instance). But this is not how lerna-changelog works and porting the feature there seems unlikely. Is it okay to abandon the feature?

[rwjblue]

I'm definitely in favor, thanks for working on this!

[rwjblue]

@dcyriller - Might want to remove bin/changelog too though.

[dcyriller]

indeed, it should be gone now

[snewcomer]

This would be very helpful. I'm in favor of it. If you have time, possible we could resolve conflicts and then we can talk about it at the weekly meeting.

[dcyriller]

@snewcomer I rebased and resolved the conflicts. Your meeting is pretty late for me (11pm if I remember well). But if you need me to explain the PR, feel free to reach out, I could do it once.

Also, please don't forget that this PR would require making two changes to the repository's labels:

• you would have to create a changelog:breaking label for breaking changes
• and remove the changelog:security label (it has been used only once for a dependabot dep ugprade).

[runspired]

@rwjblue was this ever discussed? I didn't see anything in the meeting notes from last fall.