404 when running pg:router

Everything work before run `npm run pg:router`.

1. No dependency defined at package.json. Actually need `npm install @apollo/rover`.
2. error when running:
```
> mongodb-chatbot-framework-quick-start@1.0.0 pq:router
> APOLLO_ROVER_DEV_ROUTER_VERSION=2.0.0-preview.0.0 rover dev --supergraph-config graph/supergraph.yaml --router-config graph/router.yaml

** Notice: Changes in This Release! **
This version includes significant updates to the `rover dev` command.
We highly recommend reviewing the updated documentation to ensure a smooth experience.
Read more: https://www.apollographql.com/docs/rover/commands/dev

warning: Do not run this command in production! It is intended for local development only.

merging supergraph schema files
supergraph config loaded successfully
By installing this plugin, you accept the terms and conditions outlined by this license.
More information on the ELv2 license can be found here: https://go.apollo.dev/elv2.
Do you accept the terms and conditions of the ELv2 license? [y/N]
y
downloading the 'supergraph' plugin from https://rover.apollo.dev/tar/supergraph/aarch64-apple-darwin/v2.10.0-preview.0
the 'supergraph' plugin was successfully installed to /Users/cyrbuzz/Desktop/work/graphchat/node_modules/@apollo/rover/binary/supergraph-v2.10.0-preview.0
starting a session with the 'connector' subgraph
==> Watching /Users/cyrbuzz/Desktop/work/graphchat/graph/schema.graphql for changes
composing supergraph with Federation 2.10.0-preview.0
downloading the 'router' plugin from https://rover.apollo.dev/tar/router/aarch64-apple-darwin/v2.0.0-preview.0.0
error: unable to find dependency: "error: HTTP status client error (404 Not Found) for url (https://rover.apollo.dev/tar/router/aarch64-apple-darwin/v2.0.0-preview.0.0)
```

https://rover.apollo.dev/tar/router/aarch64-apple-darwin/v2.0.0-preview.0.0

The URL indeed is 404.

Start with package.json and the `pg:router` script, then inspect graph/supergraph.yaml and graph/router.yaml. Run `npm run pg:router` and compare the configured Rover and router versions with the available download URL. Done means the documented dependency and command no longer request the unavailable router artifact.

Written by the indexing model from the issue text.