Bump xunit from 2.7.1 to 2.8.0

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>

Author: dependabot[bot]

XmlSchemaClassGenerator.Tests/XmlSchemaClassGenerator.Tests.csproj

@@ -40,9 +40,9 @@
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
     </PackageReference>
-    <PackageReference Include="xunit" Version="2.7.1" />
-    <PackageReference Include="xunit.extensibility.core" Version="2.7.1" />
-    <PackageReference Include="xunit.extensibility.execution" Version="2.7.1" />
+    <PackageReference Include="xunit" Version="2.8.0" />
+    <PackageReference Include="xunit.extensibility.core" Version="2.8.0" />
+    <PackageReference Include="xunit.extensibility.execution" Version="2.8.0" />
   </ItemGroup>
   <PropertyGroup>
     <SonarQubeExclude>true</SonarQubeExclude>