fix(dashboard): use blockquote instead of invalid ul (#15612)

...ry/__fixtures__/master-issue_with_2_PR_closed_ignored.txt

...repository/__fixtures__/master-issue_with_2_PR_edited.txt

...itory/__fixtures__/master-issue_with_3_PR_in_approval.txt

...itory/__fixtures__/master-issue_with_3_PR_in_progress.txt

...orkers/repository/__fixtures__/master-issue_with_8_PR.txt

...epository/__snapshots__/dependency-dashboard.spec.ts.snap

lib/workers/repository/dependency-dashboard.ts

lib/workers/repository/package-files.ts

tsconfig.strict.json