Bug 1575369 - disabled browser_ext_sidebarAction_incognito.js on all platforms r=gbrown

Differential Revision: https://phabricator.services.mozilla.com/D43972

--HG--
extra : moz-landing-system : lando

browser/components/extensions/test/browser/browser.ini

@@ -199,6 +199,7 @@ skip-if = debug # Bug 1394984 disable debug builds on all platforms
 [browser_ext_sidebarAction_context.js]
 [browser_ext_sidebarAction_contextMenu.js]
 [browser_ext_sidebarAction_incognito.js]
+skip-if = true # Bug 1575369
 [browser_ext_sidebarAction_runtime.js]
 [browser_ext_sidebarAction_tabs.js]
 [browser_ext_sidebarAction_windows.js]