Bug 1805893 - Skip test_initial_download.py on Windows ccov builds. r=webdriver-reviewers,whimboo

Differential Revision: https://phabricator.services.mozilla.com/D164810

testing/firefox-ui/tests/functional/safebrowsing/manifest.ini

@@ -1,6 +1,7 @@
 [test_initial_download.py]
 skip-if =
   (debug || asan || tsan) # The GAPI key isn't available in debug or sanitizer builds
+  (ccov && os == 'win') # Bug 1805893
   (cc_type == 'clang' && os == 'win') # Bug 1565818
 [test_notification.py]
 [test_warning_pages.py]