fix(dialog): handle auto-dismiss races

[naps (Tib-Gridello)]

Summary

• ignore failed best-effort dialog auto-dismissals when another CDP client handles the dialog first
• cover the race in the existing two-client CDP test

Fixes #42827

[naps (Tib-Gridello)]

@microsoft-github-policy-service agree

[github-actions]

Test results for "tests 1"

5 flaky

⚠️ [chromium-library] › library/video.spec.ts:762 › screencast › should work with video+trace `@chromium-ubuntu-22.04-node22`
⚠️ [firefox-library] › library/browsercontext-cookies-third-party.spec.ts:257 › third party 'Partitioned;' cookies `@firefox-ubuntu-22.04-node20`
⚠️ [firefox-library] › library/browsercontext-cookies-third-party.spec.ts:470 › top level 'Partitioned;' cookie and same origin iframe `@firefox-ubuntu-22.04-node20`
⚠️ [firefox-page] › page/page-goto.spec.ts:90 › should work with Cross-Origin-Opener-Policy `@firefox-ubuntu-22.04-node20`
⚠️ [webkit-page] › page/frame-goto.spec.ts:31 › should reject when frame detaches `@webkit-ubuntu-22.04-node20`

52020 passed, 1250 skipped

---

Merge workflow run.

[github-actions]

Test results for "MCP"

8692 passed, 1474 skipped

---

Merge workflow run.

[Mohamed Sharif (MSH4R1F)]

Thanks for this fix. We hit the same race in production: a page dialog opened while two CDP clients were connected, the auto-dismiss rejected, and the unhandled rejection crashed the Node process.

We work around it by answering dialogs ourselves on every client we connect. That still leaves a short window between a client connecting and its listener being in place.

Could this go into a 1.63.x patch release? If not, we will wait for 1.64.0.