Bump the xunit group with 1 update (#76)

Bumps the xunit group with 1 update: [xunit](https://github.com/xunit/xunit).


Updates `xunit` from 2.6.2 to 2.6.4
- [Commits](xunit/xunit@2.6.2...2.6.4)

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

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

tests/Yoh.Text.Json.NamingPolicies.Tests.csproj

@@ -7,7 +7,7 @@
  <ProjectReference Include="..\src\Yoh.Text.Json.NamingPolicies.csproj" />
  <PackageReference Include="System.Memory" Version="4.5.5" />
  <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
- <PackageReference Include="xunit" Version="2.6.2" />
+ <PackageReference Include="xunit" Version="2.6.4" />
  <PackageReference Include="xunit.runner.visualstudio" Version="2.5.6">
  <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
  <PrivateAssets>all</PrivateAssets>