test: fix flaky Windows CI timeouts in browser tests (#1806)

## Summary

- Replace `asyncio.sleep` with `asyncio.Event().wait()` in adaptive playwright timeout test and increase timeout from 1s to 10s.
- Increase Firefox `operation_timeout` from 15s to 60s in browser pool test.

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: vdusek

tests/unit/browsers/test_browser_pool.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+from datetime import timedelta
 from typing import TYPE_CHECKING
 from unittest.mock import AsyncMock
 
@@ -103,7 +104,10 @@ async def test_new_page_with_each_plugin(server_url: URL) -> None:
 
 @run_alone_on_mac
 async def test_with_default_plugin_constructor(server_url: URL) -> None:
-    async with BrowserPool.with_default_plugin(headless=True, browser_type='firefox') as browser_pool:
+    # Use a generous operation timeout so that Firefox has enough time to launch on slow Windows CI.
+    async with BrowserPool.with_default_plugin(
+        headless=True, browser_type='firefox', operation_timeout=timedelta(seconds=60)
+    ) as browser_pool:
         assert len(browser_pool.plugins) == 1
         assert isinstance(browser_pool.plugins[0], PlaywrightBrowserPlugin)
 

tests/unit/crawlers/_adaptive_playwright/test_adaptive_playwright_crawler.py

@@ -576,15 +576,17 @@ async def test_adaptive_playwright_crawler_timeout_in_sub_crawler(test_urls: lis
     crawler.
     """
     static_only_predictor_no_detection = _SimpleRenderingTypePredictor(detection_probability_recommendation=cycle([0]))
-    request_handler_timeout = timedelta(seconds=1)
+    # Use a generous timeout so the static pipeline has enough time to reach the handler even on slow CI.
+    # The handler will block indefinitely, so the timeout will always fire during the handler's wait.
+    request_handler_timeout = timedelta(seconds=10)
 
     crawler = AdaptivePlaywrightCrawler.with_beautifulsoup_static_parser(
         max_request_retries=0,
         rendering_type_predictor=static_only_predictor_no_detection,
         request_handler_timeout=request_handler_timeout,
     )
-    mocked_static_handler = Mock()
-    mocked_browser_handler = Mock()
+    mocked_static_handler = Mock(name='static_handler')
+    mocked_browser_handler = Mock(name='browser_handler')
 
     @crawler.router.default_handler
     async def request_handler(context: AdaptivePlaywrightCrawlingContext) -> None:
@@ -596,13 +598,13 @@ async def request_handler(context: AdaptivePlaywrightCrawlingContext) -> None:
             mocked_static_handler()
             # Relax timeout for the fallback browser request to allow for slow browser startup on CI
             crawler._request_handler_timeout = timedelta(seconds=120)
-            # Sleep for time obviously larger than top crawler timeout.
-            await asyncio.sleep(request_handler_timeout.total_seconds() * 3)
+            # Block indefinitely - will be cancelled when the request_handler_timeout fires.
+            await asyncio.Event().wait()
 
     await crawler.run(test_urls[:1])
 
     mocked_static_handler.assert_called_once_with()
-    # Browser handler was capable of running despite static handler having sleep time larger than top handler timeout.
+    # Browser handler was capable of running despite static handler blocking longer than the handler timeout.
     mocked_browser_handler.assert_called_once_with()