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

[kahest]

Description

Today, in the Cocoa 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).

Note that this is specifically relevant for Cocoa (and JS) because we have legacy workarounds in place in Relay for these SDKs.

[kahest]

PR that implements this on sentry-javascript: getsentry/sentry-javascript#17364