chore(workflows): run changelog check in CI for every public package

[acstll]

Summary

This PR updates the "Changelog required" workflow.

As of now, the check will pass if there's a changelog file present anywhere in packages/*, regardless of the number of public packages that actually contain changes. This update makes sure the check in done for every public package that has changes.

For example, the check will fail with "❌ Changelog file for PR # is missing in package 'eui-theme-borealis'" if:

• the PR has changes in 2 packages: eui and eui-theme-borealis
• there is only a changelog file for eui

Important

PR made with the help of AI, but carefully reviewed by a human (myself)

Why are we making this change?

To avoid issues while publishing packages, where a package expected to be published does not… (see #9007)

Resolves https://github.com/elastic/eui-private/issues/416

Impact to users

No impact, this is a change affecting only how the repo works.

QA

Do you know a good way to test this before actually merging? 😑

[weronikaolejniczak]

💡 This check is meant to be triggered by PRs. So a possible way to test it is simply basing a new branch off this one, and making appropriate changes:

• changing eui and eui-theme-borealis, and supplying both changelogs (should pass)
• changing eui and eui-theme-borealis, supplying a changelog for eui and using skip-changelog:eui-theme-borealis (should pass)
• changing eui and eui-theme-borealis, using skip-changelog (should pass)
• changing eui and eui-theme-borealis, not supplying a changelog for eui and using skip-changelog:eui-theme-borealis (should fail)
• changing eui and eui-theme-borealis, supplying a changelog for eui and using skip-changelog:eui (should fail)

maybe some other cases worth testing.

[weronikaolejniczak]

This looks good to me, Arturo! 🟢 Thanks for doing this.

I'd wait for Tomasz to review.