test: Deflake adaptive crawler timeout test against slow CI browser navigation

[vdusek]

test_adaptive_playwright_crawler_timeout_in_sub_crawler fails intermittently on Windows CI with
Expected 'browser_handler' to be called once. Called 0 times.
(example run).
The fallback browser request navigates under the Playwright sub-crawler's own navigation_timeout
(default 1 minute) - a budget separate from the request handler timeout the test already relaxes to
120s. On a saturated runner (8 xdist workers, each driving Chromium) page.goto can exceed it, and
with max_request_retries=0 that single slow navigation fails the only attempt before the handler
ever runs.

The test now grants navigation the same 120s ceiling via playwright_crawler_specific_kwargs. To
pass that type-safely, the missing navigation_timeout key is added to
_PlaywrightCrawlerAdditionalOptions - typing only, PlaywrightCrawler.__init__ already accepts it.

Verified by deterministic fault injection (a playwright-only pre-navigation delay consuming the
shared navigation budget): a 70s navigation-phase delay reproduces the exact CI failure under the
default ceiling and passes under the 120s one. After the fix, 0/96 failures across 8 concurrent
Chromium-saturated lanes, and the adaptive + playwright test modules pass under -n auto. The
assertions are unchanged.

✍️ Drafted by Claude Code

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.73%. Comparing base (7e71d70) to head (c7df284).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2207      +/-   ##
==========================================
- Coverage   93.74%   93.73%   -0.01%     
==========================================
  Files         181      181              
  Lines       12852    12854       +2     
==========================================
+ Hits        12048    12049       +1     
- Misses        804      805       +1     

Flag	Coverage Δ
unit	93.73% <100.00%> (-0.01%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.