CI: Add concurrency checks to PR workflows (#6000)

## Summary


https://docs.github.com/en/actions/reference/workflows-and-actions/workflow-syntax#example-only-cancel-in-progress-jobs-or-runs-for-the-current-workflow

## Changes

- **What**: Will cancel ongoing checks when new commits are pushed to
the PR branch

## Review Focus

What other optimizations could we make?

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-6000-CI-Add-concurrency-checks-to-PR-workflows-2876d73d3650813cbb65eb8c397ac748)
by [Unito](https://www.unito.io)

.github/workflows/update-playwright-expectations.yaml

@@ -8,7 +8,8 @@ on:
     types: [created]
 
 concurrency:
-  group: ${{ github.event.number || github.event.issue.number }}
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
 
 jobs:
   test: