Bug 1666843 - disable browser_pointerlock_warning.js on Linux debug fission DONTBUILD

Differential Revision: https://phabricator.services.mozilla.com/D92776

dom/tests/browser/browser.ini

@@ -77,6 +77,7 @@ support-files =
 support-files =
   test_mixed_content_image.html
 [browser_pointerlock_warning.js]
+skip-if = fission && (os == 'linux') && debug # Bug 1666843
 [browser_sessionStorage_navigation.js]
 support-files =
   file_empty.html