[JoshuaFrenchwood]

What was changed

Updated the Core pin to f49305f1, ran poe update-core, and regenerated the bindings. This includes temporalio/sdk-rust#1717, which passes the propagated Nexus serialization context from the server to lang on:

• InitializeWorkflow, from the workflow-started event
• DoUpdate, from the update request
• the activity Start task, from the poll response

The regenerated API protos add propagated_nexus_serialization_context on the start workflow, start activity and update requests, and on the history, poll and update responses that return it.

This is the first of 3 stacked PRs:

1. This PR: Core update
2. Nexus serialization context workflows activities #2043 : propagate the context to workflows and standalone activities
3. Propagate Nexus serialization context to workflow updates #2045 : propagate the context to workflow updates

Why?

Checklist

1. Closes

2. How was this tested:

3. Any docs updates needed?