docs(browsercontext): undeprecate setHTTPCredentials

[Dmitry Gozman (dgozman)]

Summary

• Remove the deprecated annotation from BrowserContext.setHTTPCredentials.
• Document instead that browsers may cache credentials per origin, so changing credentials for an already-authenticated origin may have no effect.

[github-actions]

Test results for "tests 1"

3 flaky

⚠️ [chromium-library] › library/chromium/chromium.spec.ts:213 › should intercept service worker requests (main and within) `@chromium-ubuntu-22.04-node24`
⚠️ [chromium-library] › library/video.spec.ts:664 › screencast › should capture full viewport `@chromium-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`

51262 passed, 1237 skipped

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Merge workflow run.