Remove metricsAggregatorIntegration from snippets


This is not needed in javascript v8.
![Image](https://github.com/getsentry/sentry/assets/9060071/ac652c82-5dfa-4d71-8f47-d33743437ebe)


Relates to:
https://github.com/getsentry/sentry-docs/pull/10082
```[tasklist]
### Tasks
- [ ] product change
- [ ] docs change
```
