chore(deps): update @testing-library/dom to 7.28.1 (#306)

Author: ddehart

package-lock.json

@@ -42,7 +42,7 @@
     "@primer/octicons-react": "^10.0.0",
     "@reach/dialog": "^0.10.5",
     "@reach/menu-button": "^0.9.1",
-    "@testing-library/dom": "^7.22.5",
+    "@testing-library/dom": "^7.28.1",
     "@testing-library/user-event": "^12.1.2",
     "codemirror": "5.54.0",
     "crx-bridge": "^2.1.0",