Update Rust crate serial_test to v3

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
serial_test	dev-dependencies	major	2.0.0 -> 3.0.0

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Release Notes

palfrey/serial_test (serial_test)

### [`v3.0.0`](https://togithub.com/palfrey/serial_test/releases/tag/v3.0.0) [Compare Source](https://togithub.com/palfrey/serial_test/compare/v2.0.0...v3.0.0) #### What's Changed - Multi key support [https://github.com/palfrey/serial_test/pull/102](https://togithub.com/palfrey/serial_test/pull/102) - Attributes like `#[serial(one, two)]` are now supported (for all attributes) - This is a breaking change, as `file_serial` paths now need to be done separately `#[file_serial(key, path => "/tmp/foo")]` - Attributes at a mod-level [https://github.com/palfrey/serial_test/pull/104](https://togithub.com/palfrey/serial_test/pull/104) - You can set any of the attributes on a `mod` and all `#[test]` fn's in that mod will have the attribute applied. **Full Changelog**: https://github.com/palfrey/serial_test/compare/v2.0.0...v3.0.0

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