deps: update dependency nunit to v4.2.1

[renovate-bot]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
NUnit (source)	4.2.0 -> 4.2.1

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Release Notes

nunit/nunit (NUnit)

### [`v4.2.1`](https://togithub.com/nunit/nunit/compare/4.2.0...4.2.1) [Compare Source](https://togithub.com/nunit/nunit/compare/4.2.0...4.2.1)

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