Update Galata to fix notification toasts in screenshots

Author: jasongrout

ui-tests/package.json

@@ -15,7 +15,7 @@
   "author": "Project Jupyter",
   "license": "BSD-3-Clause",
   "devDependencies": {
-    "@jupyterlab/galata": "^4.4.2",
+    "@jupyterlab/galata": "^4.5.1",
     "yarn-deduplicate": "^6.0.1"
   }
 }