Bug 1776940 - Part 2: Re-enable test_mixed_principals.html on Windows r=aosmond

Depends on D197553

Differential Revision: https://phabricator.services.mozilla.com/D197554

dom/media/test/mochitest.toml

@@ -864,7 +864,6 @@ tags = "mtg"
 skip-if = [
   "os == 'android'", # bug 1309814, android(bug 1232305)
   "apple_silicon", # bug 1707737
-  "win11_2009 && !debug", # Bug 1776940
 ]
 
 ["test_mp3_broadcast.html"]