test: roll stable-test-runner to 1.64.0-alpha-2026-09-28

[microsoft-playwright-automation]

No description provided.

[github-actions]

Test results for "tests 1"

5 flaky

⚠️ [chromium-library] › library/chromium/chromium.spec.ts:301 › should report intercepted service worker requests in HAR `@frozen-time-library-chromium-linux`
⚠️ [chromium-library] › library/inspector/cli-codegen-2.spec.ts:105 › cli codegen › should upload a single file `@chromium-ubuntu-22.04-node20`
⚠️ [chromium-library] › library/chromium/chromium.spec.ts:301 › should report intercepted service worker requests in HAR `@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`

52299 passed, 1243 skipped

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Merge workflow run.

[github-actions]

Test results for "MCP"

1 failed
❌ [firefox] › mcp/cli-core.spec.ts:131 › check @mcp-windows-latest-firefox

8763 passed, 1480 skipped

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Merge workflow run.

[github-actions]

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

🟢 The one failure is a known Windows Firefox flake

mcp/cli-core.spec.ts:131 › check failed only on mcp-windows-latest-firefox. It has failed the same way on main and on unrelated PRs, and this PR only bumps tests/playwright-test/stable-test-runner, which the MCP CLI tests don't use.

Details

This PR changes only tests/playwright-test/stable-test-runner/package.json and its lockfile. That package is used by the test-runner suite. The MCP suite never loads it, so the diff can't reach this test.

Pre-existing flake / infra

• [firefox] › mcp/cli-core.spec.ts:131 › check (@mcp-windows-latest-firefox): a pre-existing flake. In the test-results DB, this test failed in 10 of 705 runs (~1.4%) on mcp-windows-latest-firefox. It passed every time on Ubuntu (711 runs) and macOS (716 runs). The failures cover SHAs this PR can't be responsible for, including main (b8627f95, 9ae53771, d1ead3ec) and PRs fix(webkit): allow service worker navigation while offline #42894, feat(evaluate): opt in to Map and Set serialization #42709, chore: replace manual dispose and similar things with using #42685, fix(fetch): preserve node error fields across serialization #42562, chore: bump WebKit version to 26.6 #42514, fix(video): embed recording start time in WebM metadata #42478 and fix(tracing): allow restarting tracing after a failed stop #42425. The usual error matches this run: the snapshot is missing [checked] (and sometimes [active]), e.g. Received string: "- checkbox [ref=e2]". That points to a Windows Firefox race between the check action and the next snapshot.

_{Triaged by the Playwright bot - agent run}