build(icon): minimum tokens version with xxl and xxs sizing

Update required tokens version with a minimum of the latest release that
includes the new custom-vars for the xxl and xxs workflow icon sizes.

Author: jawinn

components/icon/package.json

@@ -15,7 +15,7 @@
   },
   "main": "dist/index.css",
   "peerDependencies": {
-    "@spectrum-css/tokens": ">=11.4"
+    "@spectrum-css/tokens": ">=13.1"
   },
   "publishConfig": {
     "access": "public"