Bug 1866777 - Disable test_race_cache_with_network.js on windows opt for frequent failures. r=#intermittent-reviewers,jmaher

Differential Revision: https://phabricator.services.mozilla.com/D197199

Author: CosminSabou

netwerk/test/unit/xpcshell.toml

@@ -973,6 +973,9 @@ skip-if = [
 ["test_psl.js"]
 
 ["test_race_cache_with_network.js"]
+skip-if = [
+  "os == 'win' && !debug", # Bug 1866777
+]
 
 ["test_range_requests.js"]