Bump xunit from 2.7.1 to 2.8.0 (#177)

Bumps [xunit](https://github.com/xunit/xunit) from 2.7.1 to 2.8.0.
- [Commits](xunit/xunit@2.7.1...2.8.0)

---
updated-dependencies:
- dependency-name: xunit
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Tests/GuiStracini.Mandae.Tests/GuiStracini.Mandae.Tests.csproj

@@ -19,7 +19,7 @@
       <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>
-    <PackageReference Include="xunit" Version="2.7.1" />
+    <PackageReference Include="xunit" Version="2.8.0" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.8.0">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>