[QA] Skip contexts in quarantine

What does this MR do?

Tests were already skipped when tagged :quarantine. This MR skips contexts as well.

This avoids running before/after blocks for tests that are in quarantine (e.g., https://gitlab.com/gitlab-org/gitlab-qa/-/jobs/156102815)

What are the relevant issue numbers?

https://gitlab.com/gitlab-org/quality/team-tasks/issues/80

Does this MR meet the acceptance criteria?

• [-] Changelog entry added, if necessary
• [-] Documentation created/updated via this MR
• [-] Documentation reviewed by technical writer or follow-up review issue created
• [-] Tests added for this feature/bug
• [-] Tested in all supported browsers
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides
• [-] Link to e2e tests MR added if this MR has Requires e2e tests label. See the Test Planning Process.
• [-] Security reports checked/validated by reviewer