Remove dead endpoints

[neekolas]

AI Assisted Summary

TL;DR

Removed deprecated MLS API methods and updated related functionality.

What changed?

• Removed register_installation method from XmtpMlsClient trait and its implementations.
• Removed get_identity_updates method from XmtpMlsClient trait and its implementations.
• Removed related types and imports for these deprecated methods.
• Updated tests to reflect these changes.

How to test?

1. Ensure all existing tests pass after removing the deprecated methods.
2. Verify that any code previously using register_installation now uses upload_key_package instead.
3. Check that no code is relying on the removed get_identity_updates functionality.

Why make this change?

This change is part of an effort to streamline the MLS API by removing deprecated methods. The register_installation method has been replaced by upload_key_package, and get_identity_updates is no longer needed. Removing these methods simplifies the API, reduces maintenance overhead, and ensures that clients are using the most up-to-date methods for interacting with the MLS system.

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[neekolas]

• Stop setting new lifetimes #964
• Remove dead endpoints #963 👈
• Upload key package before publishing identity updates #962
• main

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Merge activity

• Aug 14, 5:32 PM PDT: @neekolas started a stack merge that includes this pull request via Graphite.
• Aug 14, 5:35 PM PDT: Graphite rebased this pull request as part of a merge.
• Aug 14, 5:41 PM PDT: @neekolas merged this pull request with Graphite.
• Aug 27, 10:34 AM PDT: @neekolas started a stack merge that includes this pull request via Graphite.