Accessibility: Enable accessibilityAudit on different pages in our integration tests

[umpox]

Problem statement

We recently added accessibilityAudit to our integration tests (https://github.com/sourcegraph/sourcegraph/pull/32895). It will test the current page for accessibility and fail with any errors.

We should aim to use this in all areas where we use percySnapshot

Success criteria

We have enabled accessibilityAudit in all the areas where we use percySnapshot in the integration tests.

Implementation details

Here's how we should implement:

1. Add accessibilityAudit in the same place where we call percySnapshot in the integration tests.
2. Run the tests locally and observe any failures. See the above PR for example output.

To fix the failures, we should:

a. If it's simple or quick to fix, then make the changes on the branch. There should be relevant documentation attached to the test error that will help you work out how to fix this.
b. If it's complex, or will take a long time to fix. Add the a11y-ignore class to exclude the element from the audit, raise an issue specifically to solve this problem, leave a comment next to the class with a link to the issue.

Useful links:
accessibilityAudit
Accessibility documentation to help debug

Time estimate

We should not spend more than 4 hours per addition of accessibilityAudit. If we find ourselves taking more than that, we should create a separate issue for the complex problems.

[gitstart-app]

Here is the GitStart Ticket for this issue: https://app.gitstart.com/clients/sourcegraph/tickets/SG-33093

[gitstart-sourcegraph]

@umpox We have some instances of monaco-editor breaking accessibility with landmark-unique rule, due to there being two .monaco-status divs with role=complementary but no aria-label. Here's an existing issue that highlights this, I believe this issue should be resolved in later versions of monaco-editor than we have at the moment (v0.24.0). WDYT about spending some time to upgrade monaco-editor to version to resolve this, or an alternative solution perhaps?. Considering it's a dynamically generated element, disabling accessibilityAudit might be tricky.

[umpox]

@gitstart-sourcegraph It appears actually that bug has not been fixed, so we'll have to add an additional workaround here.

Let's update this line to take an array of ignored classes, so we can still ignore even if it is dynamically added.

    const axe = new AxePuppeteer(page).exclude([
        ACCESSIBILITY_AUDIT_IGNORE_CLASS,
        '.monaco-status', // https://github.com/microsoft/monaco-editor/issues/2448
    ])