Bug 1613516 - Disable widget/tests/browser/browser_test_clipboardcache.js on Linux coverage builds as it consistently times out. r=aryx

Depends on D61994

Differential Revision: https://phabricator.services.mozilla.com/D61995

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

widget/tests/browser/browser.ini

@@ -6,6 +6,6 @@ support-files =
   dummy.html
 
 [browser_test_clipboardcache.js]
-skip-if = os == 'android'
+skip-if = os == 'android' || (os == 'linux' && ccov) # Bug 1613516, the test consistently timeouts on Linux coverage builds.
 [browser_test_procinfo.js]
 skip-if = os == "android" || (ccov && os == "linux") # https://bugzilla.mozilla.org/show_bug.cgi?id=1608080