Fix Percy tests being queued against PRs with Percy label when the ne…

[jmuzina]

Fixes Percy tests being triggered against PRs that have the Percy label on label events when the label that was just applied is not the Percy needed label.

The logic has been refined as such:

• If the trigger was a PR synchronization (push to a live PR), Percy is run if the PR has the Percy needed label.
• If the trigger was a label being added to the PR, Percy is run if the new label is the Percy needed label.

QA

• Review QA PR; its comments demonstrate all use cases covered by this change
• Verify the actions YAML code for the if conditional in the QA PR is identical to the proposed code for this PR, with the exception of the echo job that is used for QA output.

Check if PR is ready for release

If this PR contains Vanilla SCSS code changes, it should contain the following changes to make sure it's ready for the release:

• [x] PR should have one of the following labels to automatically categorise it in release notes:
  • Feature 🎁, Breaking Change 💣, Bug 🐛, Documentation 📝, Maintenance 🔨.
• [ ] Vanilla version in package.json should be updated relative to the most recent release, following semver convention:
  • if CSS class names are not changed it can be bugfix relesase (x.x.X)
  • if CSS class names are changed/added/removed it should be minor version (x.X.0)
  • see the wiki for more details
• [ ] Any changes to component class names (new patterns, variants, removed or added features) should be listed on the what's new page.

[webteam-app]

Demo

Jenkins

demos.haus

[jmuzina]

@bartaz @pastelcyborg Be careful applying labels to PRs that already have the Percy label on them until this is merged - they'll run Percy tests multiple times. I've been manually cancelling runs against workflows that were already tested; we should merge this asap, then rebase effected PRs

• [x] #5178
• [ ] #5182
• [x] #5183
• [ ] #5185
• [ ] #5189
• [ ] #5192
• [x] #5193
• [x] #5107

I've removed the Percy label from those PRs in the meantime.