Add playwright to make sure that pixels are not smorgulated when we burf the flapitulator

[KevinMind]

Fixes: mozilla/addons#ISSUENUM

Description

Add playwright to get snapshots of all our pages to make sure we don't break any big things along the way with future planned updates to revtools and devhub

Context

We need to land #23049 first as it enables running the app in prod mode without needing prod auth so we can get snapshots as we would expect in the wild

Testing

TBD

Checklist

• Add #ISSUENUM at the top of your PR to an existing open issue in the mozilla/addons repository.
• Successfully verified the change locally.
• The change is covered by automated tests, or otherwise indicated why doing so is unnecessary/impossible.
• Add before and after screenshots (Only for changes that impact the UI).
• Add or update relevant docs reflecting the changes made.