Attempt to resolve some e2e test flakiness

[qroll]

Description of changes

• Remove font check: seems like Playwright includes it as part of navigation already - tested by loading a font with a delay
• Update breadcrumb scrolling steps
• Error display: using variable seems flaky. On further thought images are sized by pixel so it will only look good on specific screen sizes as well (independent of theme), so hardcoding might be the more appropriate option