Lighthouse CI: Add retry logic

Created by: umpox

Noticed some potential flakiness in Puppeteer: https://buildkite.com/sourcegraph/sourcegraph-async/builds/22894#08993bc0-9e75-4e58-9b4a-3279e37cc729

Going to see if we can avoid any failures, but this PR adds retry logic so it is similar to our other Puppeteer tests.

Note: This means that a Lighthouse test could take up to 6 minutes, but it won't hold this pipeline up as the Chromatic step still takes far longer.

Note: We'll generate this pipeline as part of https://github.com/sourcegraph/sourcegraph/issues/25636