ci: use Rust 1.96.1 in CI

[ClementTsang]

Description

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Should fix the weird sporadic network failures.

Issue

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Closes: #

Testing

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• Windows
• macOS (specify version below)
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Checklist

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• If this PR adds or changes a dependency, please justify this in the description
• If this is a code change, areas your change affects have been linted using (cargo fmt)
• If this is a code change, your changes pass cargo clippy --all -- -D warnings
• If this is a code change, new tests were added if relevant
• If this is a code change, your changes pass cargo test
• The change has been verified to work (see the Testing section) and doesn't unexpectedly break anything else
• Documentation has been updated if needed (README.md, help menu, docs, configs, etc.)
• There are no merge conflicts
• You have personally reviewed your changes already before creating the PR
• The pull request passes the provided CI pipeline
• If this PR was generated with AI, please specify how in the "Other" section, and that you as a human have personally reviewed it

Other

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