Smoke: accessibility tests are flaky

[bpasero]

Observing them to fail on macOS Browser, for example:

• https://github.com/microsoft/vscode/actions/runs/20836704389/job/59862767958?pr=286642#step:26:131
• https://github.com/microsoft/vscode/actions/runs/20847349036/job/59897288303#step:26:131

I am disabling them as part of #286687