test(webkit): reenable WebSocket handshake HAR coverage

[Devin Rousso (dcrousso)]

the upstream WebKit fix restores the reported WebSocket handshake headers on macOS 26

remove the platform skip so the existing HAR assertions run again

see #42205

[github-actions]

Test results for "tests 1"

9 flaky

⚠️ [chromium-library] › library/browsertype-connect.spec.ts:922 › run-server › socks proxy › should proxy ipv6 localhost requests Radoslav Kirilov (@smoke) `@chromium-ubuntu-22.04-arm-node20`
⚠️ [chromium-library] › library/video.spec.ts:664 › screencast › should capture full viewport `@chromium-ubuntu-22.04-arm-node20`
⚠️ [chromium-library] › library/video.spec.ts:736 › screencast › should work with video+trace `@chromium-ubuntu-22.04-node24`
⚠️ [chromium-library] › library/popup.spec.ts:260 › should not throw when click closes popup `@chromium-ubuntu-22.04-node20`
⚠️ [chromium-library] › library/screencast.spec.ts:28 › screencast.start delivers frames via onFrame callback `@chromium-ubuntu-22.04-node20`
⚠️ [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-emulate-media.spec.ts:144 › should keep reduced motion and color emulation after reload `@firefox-ubuntu-22.04-node20`
⚠️ [firefox-page] › page/page-event-request.spec.ts:181 › should return response body when Cross-Origin-Opener-Policy is set `@firefox-ubuntu-22.04-node20`

51308 passed, 1246 skipped

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Merge workflow run.

[github-actions]

Test results for "MCP"

3 failed
❌ [chrome] › mcp/cli-save-as.spec.ts:48 › screenshot --filename @mcp-ubuntu-latest-chrome
❌ [firefox] › mcp/cli-core.spec.ts:97 › fill @mcp-windows-latest-firefox
❌ [firefox] › mcp/cli-core.spec.ts:115 › hover @mcp-windows-latest-firefox

8272 passed, 1371 skipped

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Merge workflow run.

[github-actions]

Hi, I'm the Playwright bot and I took a first look at the failing CI here.

🟢 The failures are pre-existing MCP flakes — this PR is clear

This PR removes a single WebKit-only it.fixme in tests/library/har-websocket.spec.ts. The three red tests are all in the MCP CLI suite on Chromium and Firefox — nothing the diff can reach. Each one has a flake history on unrelated SHAs/PRs, so none of them is caused by this change.

Details

Overall assessment: the only failing check jobs were ubuntu-latest - chrome and windows-latest - firefox (MCP). All WebKit jobs — the only engine this PR touches — passed. The three flagged failures live in mcp/cli-core.spec.ts and mcp/cli-save-as.spec.ts, which don't exercise the WebSocket HAR path.

Pre-existing flake / infra

• [firefox] › mcp/cli-core.spec.ts:115 › hover — long-standing flake. In the aggregated CI results it fails/rescues across many runs the PR can't own: main (sha bee00ad3a, 12b611da2), release-1.62 (83768264e), and PRs feat(webkit): roll to r2339 #41975, feat(selectors): add pierceFrames context option #42033, fix(test runner): match --test-list entries against the test file path #42301, feat(selectors): replace pierceFrames() with frameLocator() #42395. Passed on retry in this run too.
• [firefox] › mcp/cli-core.spec.ts:97 › fill — same story: flakes on main (sha d529911d6, 2dec18d7e) and PR fix(mcp): disable the chromium sandbox for the bundled browser on linux #42490, independent of this branch.
• [chrome] › mcp/cli-save-as.spec.ts:48 › screenshot --filename — flaked within this very run (passed on the other attempts, failed on one), and the diff is WebKit-test-only so it can't affect a Chromium screenshot. Weaker cross-run history than the two above, but the within-run non-determinism plus zero diff reachability point to a flake, not a regression.

_{Triaged by the Playwright bot - agent run}