Update Rust crate serde to v1.0.203

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
serde (source)	dependencies	patch	1.0.202 -> 1.0.203

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Release Notes

serde-rs/serde (serde)

### [`v1.0.203`](https://togithub.com/serde-rs/serde/releases/tag/v1.0.203) [Compare Source](https://togithub.com/serde-rs/serde/compare/v1.0.202...v1.0.203) - Documentation improvements ([#​2747](https://togithub.com/serde-rs/serde/issues/2747))

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