How can I access another plugin’s registered options inside Fastify?

## 💬 Question here

I have a situation where multiple plugins are registered in my Fastify app. Each plugin can receive its own options object when registered, for example:

```js
fastify.register(require('./pluginA'), { foo: 'bar' })
fastify.register(require('./pluginB'))
````
In `pluginB`, I’d like to access the options that were passed to `pluginA`

Is there a built-in or recommended way to access another plugin’s options directly?