fix: respect custom HTTP headers in PlaywrightCrawler (#685)

### Description

add `Request.headers` support for `PlaywrightCrawler`. 

### Testing

The test uses `'https://httpbin.org/get' to ensure that the headers have
been installed

### Checklist

- [x] CI passed

---------

Co-authored-by: Vlada Dusek <v.dusek96@gmail.com>

Author: Mantisus

src/crawlee/playwright_crawler/_playwright_crawler.py

@@ -148,6 +148,8 @@ async def _navigate(
                 infinite_scroll).
         """
         async with context.page:
+            if context.request.headers:
+                await context.page.set_extra_http_headers(context.request.headers.model_dump())
             # Navigate to the URL and get response.
             response = await context.page.goto(context.request.url)
 

tests/unit/playwright_crawler/test_playwright_crawler.py

@@ -8,7 +8,7 @@
 from typing import TYPE_CHECKING
 from unittest import mock
 
-from crawlee import Glob
+from crawlee import Glob, Request
 from crawlee.fingerprint_suite._consts import (
     PW_CHROMIUM_HEADLESS_DEFAULT_SEC_CH_UA,
     PW_CHROMIUM_HEADLESS_DEFAULT_SEC_CH_UA_MOBILE,
@@ -133,6 +133,26 @@ async def request_handler(context: PlaywrightCrawlingContext) -> None:
     assert headers['User-Agent'] == PW_FIREFOX_HEADLESS_DEFAULT_USER_AGENT
 
 
+async def test_custom_headers() -> None:
+    crawler = PlaywrightCrawler()
+    response_headers = dict[str, str]()
+    request_headers = {'Power-Header': 'ring', 'Library': 'storm', 'My-Test-Header': 'fuzz'}
+
+    @crawler.router.default_handler
+    async def request_handler(context: PlaywrightCrawlingContext) -> None:
+        response = await context.response.text()
+        context_response_headers = dict(json.loads(response)).get('headers', {})
+
+        for key, val in context_response_headers.items():
+            response_headers[key] = val
+
+    await crawler.run([Request.from_url('https://httpbin.org/get', headers=request_headers)])
+
+    assert response_headers.get('Power-Header') == request_headers['Power-Header']
+    assert response_headers.get('Library') == request_headers['Library']
+    assert response_headers.get('My-Test-Header') == request_headers['My-Test-Header']
+
+
 async def test_pre_navigation_hook() -> None:
     crawler = PlaywrightCrawler()
     mock_hook = mock.AsyncMock(return_value=None)