build(deps): bump xunit from 2.6.2 to 2.6.4

Bumps [xunit](https://github.com/xunit/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
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

Directory.Packages.props

@@ -15,7 +15,7 @@
     <PackageVersion Include="NetEvolve.Extensions.XUnit" Version="1.1.144" />
     <PackageVersion Include="Polyfill" Version="1.34.0" />
     <PackageVersion Include="Verify.Xunit" Version="22.5.0" />
-    <PackageVersion Include="xunit" Version="2.6.2" />
+    <PackageVersion Include="xunit" Version="2.6.4" />
     <PackageVersion Include="xunit.core" Version="2.6.2" />
     <PackageVersion Include="xunit.runner.console" Version="2.6.2" />
     <PackageVersion Include="xunit.runner.visualstudio" Version="2.4.5" />