Freshen up dependencies

[mattgodbolt]

No description provided.

[Copilot]

Pull Request Overview

This PR updates project dependencies to their latest versions, including both runtime and development dependencies. The changes modernize the project's dependency stack while maintaining compatibility.

• Updates multiple Python packages to newer versions (anthropic, boto3, fastapi, etc.)
• Updates development tooling versions (pre-commit hooks, pytest, ruff)
• Fixes a regex pattern in tests to use raw string literal

Reviewed Changes

Copilot reviewed 4 out of 5 changed files in this pull request and generated 1 comment.

File	Description
pyproject.toml	Updates runtime and dev dependency versions to latest releases
app/test_model_costs.py	Fixes regex pattern to use raw string literal for proper escaping
app/test_explain.py	Renames unused variable to follow Python naming conventions
.pre-commit-config.yaml	Updates pre-commit hook versions to match dependency updates

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