chore(deps): update xunit-dotnet monorepo to v2.8.1

[renovate-bot]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
xunit	2.8.0 -> 2.8.1
xunit.runner.visualstudio	2.8.0 -> 2.8.1

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[!WARNING] Some dependencies could not be looked up. Check the warning logs for more information.

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Release Notes

xunit/xunit (xunit)

### [`v2.8.1`](https://togithub.com/xunit/xunit/compare/2.8.0...2.8.1) [Compare Source](https://togithub.com/xunit/xunit/compare/2.8.0...2.8.1)

xunit/visualstudio.xunit (xunit.runner.visualstudio)

### [`v2.8.1`](https://togithub.com/xunit/visualstudio.xunit/compare/2.8.0...2.8.1) [Compare Source](https://togithub.com/xunit/visualstudio.xunit/compare/2.8.0...2.8.1)

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Configuration

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♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about these updates again.

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