Temporarily skip pdf tests to unblock merging

[elceebee]

Context

Our tests related to downloading a PDF have started to fail since a chromium update. The last time the test suite passed:

ran apk add chromium chromium-chromedriver
=> (1/1) Installing chromium-chromedriver (126.0.6478.182-r0)

It started to fail when this started to happen:

apk add chromium chromium-chromedriver
=> (1/2) Upgrading chromium (126.0.6478.182-r0 -> 127.0.6533.72-r0)

Alpine does not support older versions of chromium, so we can't pin the working version.

Changes proposed in this pull request

Temporarily skip failing tests. I've created a card for investigating a replacement for Grover (which has caused us problems before). And I've put a note in my diary to check what version of Chromium is being used by Alpine in two weeks time to see if the issue has resolved itself.

Guidance to review

Link to Trello card

Things to check

• If the code removes any existing feature flags, a data migration has also been added to delete the entry from the database
• This code does not rely on migrations in the same Pull Request
• If this code includes a migration adding or changing columns, it also backfills existing records for consistency
• If this code adds a column to the DB, decide whether it needs to be in analytics yml file or analytics blocklist
• API release notes have been updated if necessary
• If it adds a significant user-facing change, is it documented in the CHANGELOG?
• Required environment variables have been updated added to the Azure KeyVault
• Inform data insights team due to database changes