Update Duo Code Review model to latest snapshot (`-20241022`)

Context

We're currently using claude-3-5-sonnet-20240620, which has been superseded by claude-3-5-sonnet-20241022.

claude-3-5-sonnet-20240620 is guaranteed available until June 2025: https://docs.anthropic.com/en/docs/resources/model-deprecations#model-status

We should switch over to the newest snapshot.

Goal

• Switch to using claude-3-5-sonnet-20241022 - see testing instructions in !173134 (merged)
• Validate there are no regressions by running the evaluations