chore(deps): update dependency @google-cloud/datastore to v6 (#1274)

Author: renovate-bot

package.json

@@ -49,7 +49,7 @@
   },
   "devDependencies": {
     "@compodoc/compodoc": "1.1.11",
-    "@google-cloud/datastore": "^5.1.0",
+    "@google-cloud/datastore": "^6.0.0",
     "@grpc/proto-loader": "^0.5.0",
     "@types/builtin-modules": "^2.0.0",
     "@types/console-log-level": "^1.4.0",