Use `settings.infer_ip` instead of `ip_address: {{auto}}`

[mydea]

Description

Today, in the browser SDK we set ip_address: {{auto}} to infer the ip address on the server.

There is now a new way to do this, documented here: https://develop.sentry.dev/sdk/data-model/event-payloads/sdk/#attributes

So we should:

• Stop setting ip_address: {{auto}}
• And instead set settings.infer_ip: 'auto' in the event metadata (if default PII is enabled)

This should make it easier to do that, as we can control this in a single place in the event processing pipeline instead of in multiple places (which is necessary today, as we also set this for standalone spans etc).