Configure solidus_chrome_headless as capybara-screenshot driver

[tvdeyen]

We have a custom driver. Capybara-screenshot needs to know about it.

Should fix errors like this

Checklist

• I have structured the commits for clarity and conciseness.
• I have added relevant automated tests for this change.

[mergify]

It looks like this PR is missing a label to determine the type of change it introduces. The maintainer should add one of the following labels:

• bug for bugfixes.
• enhancement for new features and improvements.
• documentation for documentation changes.
• security for security patches.
• removed for feature removals.
• infrastructure for internal changes that should not go in the changelog.

Additionally, the maintainer may also want to add one of the following:

• breaking for breaking changes.
• deprecated for feature deprecations.

Once the correct labels have been set, simply remove the needs changelog label label from this PR so I can merge it.

[elia]

📸 👍