Bug 1582318 - Disable browser_sharedWorker.js on fission. r=mccr8

Differential Revision: https://phabricator.services.mozilla.com/D49211

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

netwerk/cookie/test/browser/browser.ini

@@ -14,3 +14,4 @@ support-files = server.sjs
 [browser_serviceWorker.js]
 skip-if = fission && debug #Bug 1578037
 [browser_sharedWorker.js]
+skip-if = fission #Bug 1582318