fix(deps): update dependency undici to v6.21.0

[renovate[bot]]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
undici (source)	6.20.1 -> 6.21.0

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Release Notes

nodejs/undici (undici)

### [`v6.21.0`](https://redirect.github.com/nodejs/undici/compare/v6.20.1...61ec3531a64ffeec953a990c11735ff09455de4e) [Compare Source](https://redirect.github.com/nodejs/undici/compare/v6.20.1...61ec3531a64ffeec953a990c11735ff09455de4e)

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