Apply updates from cookiecutter

This automated commit applies the latest updates from our cookiecutters [1] to
this repo.

[1]: https://github.com/hypothesis/cookiecutters

.github/workflows/slack.yml

@@ -7,11 +7,12 @@ on:
 jobs:
   on-failure:
     runs-on: ubuntu-latest
-    if: ${{ github.event.workflow_run.conclusion == 'failure' }}    steps:
+    if: ${{ github.event.workflow_run.conclusion == 'failure' }}
+    steps:
       - name: Post to Slack
         uses: slackapi/[email protected]
         with:
           channel-id: 'C4K6M7P5E'
           slack-message: "A workflow run failed\n*Repo:* `${{ github.event.repository.full_name }}` (${{ github.event.repository.html_url }})\n*Workflow:* ${{ github.event.workflow.name }} (${{ github.event.workflow.html_url }})\n*Branch:* `${{ github.event.workflow_run.head_branch }}`\n*Commit:* `${{ github.event.workflow_run.head_commit.id }}`\n*Run:* ${{ github.event.workflow_run.html_url }}\n*Conclusion:* ${{ github.event.workflow_run.conclusion }}"
         env:
-          SLACK_BOT_TOKEN: ${{ secrets.SLACK_BOT_TOKEN }}
+          SLACK_BOT_TOKEN: ${{ secrets.SLACK_BOT_TOKEN }}