Update Yarn to v4 (#81575)

update yarn version

Co-authored-by: Ashley Harrison <ashley.harrison@grafana.com>

public/app/plugins/datasource/cloud-monitoring/package.json

@@ -51,5 +51,5 @@
     "build:commit": "webpack -c ./webpack.config.ts --env production --env commit=$(git rev-parse --short HEAD)",
     "dev": "webpack -w -c ./webpack.config.ts --env development"
   },
-  "packageManager": "yarn@3.6.0"
+  "packageManager": "yarn@4.0.2"
 }