Fix stale decorations (#4876)

* test changes

* fix decoration not updating

* Add changeset

* Fix lint issues

* Tests with earlier version of Node.js

* Bump node version on CI

The base typescript config uses ESNext as target, so presumably the
latest node should be used.

Co-authored-by: Dylan Schiemann <dylan@dojotoolkit.org>

package.json

@@ -110,6 +110,7 @@
     "slate-hyperscript": "workspace:*",
     "slate-react": "workspace:*",
     "source-map-loader": "^0.2.4",
+    "ts-jest": "^27.1.3",
     "typescript": "3.9.7"
   },
   "simple-git-hooks": {