Bug 1846996: Move the test variant 'xorigin' to never expire.r=jmaher,nika

Differential Revision: https://phabricator.services.mozilla.com/D187120

taskcluster/ci/test/variants.yml

@@ -101,7 +101,7 @@ no-fission:
 xorigin:
     description: "{description} with cross-origin"
     component: "Core::DOM: Content Processes"
-    expiration: "2023-09-01"
+    expiration: "never"
     suffix: "xorig"
     mozinfo: "xorigin"
     replace: