chore: fix firefox tests after switching to context delegate

[yury-s]

Follow-up to #34894

[github-actions]

Test results for "tests 1"

7 flaky

⚠️ [chromium-library] › tests/library/chromium/oopif.spec.ts:284:3 › should click @chromium-ubuntu-22.04-node22
⚠️ [firefox-page] › tests/page/page-evaluate.spec.ts:403:3 › should throw for too deep reference chain @firefox-ubuntu-22.04-node18
⚠️ [webkit-library] › tests/library/proxy.spec.ts:93:11 › should proxy local network requests › by default › localhost @webkit-ubuntu-22.04-node18
⚠️ [webkit-library] › tests/library/selector-generator.spec.ts:516:5 › selector generator › should generate exact placeholder when necessary @webkit-ubuntu-22.04-node18
⚠️ [webkit-page] › tests/page/page-filechooser.spec.ts:24:5 › should upload multiple large files @webkit-ubuntu-22.04-node18
⚠️ [webkit-page] › tests/page/page-screenshot.spec.ts:425:5 › page screenshot › should work with Array deleted @webkit-ubuntu-22.04-node18
⚠️ [webkit-page] › tests/page/page-set-input-files.spec.ts:204:5 › should upload large file with relative path @webkit-ubuntu-22.04-node18

38672 passed, 793 skipped
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Merge workflow run.