Bump xunit from 2.6.4 to 2.6.6

Bumps [xunit](https://github.com/xunit/xunit) from 2.6.4 to 2.6.6.
- [Commits](xunit/xunit@2.6.4...2.6.6)

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

Signed-off-by: dependabot[bot] <support@github.com>

FodyHelpers.Tests/FodyHelpers.Tests.csproj

@@ -18,7 +18,7 @@
     <PackageReference Include="Microsoft.CSharp" Version="4.7.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
     <PackageReference Include="Verify.Xunit" Version="22.9.0" />
-    <PackageReference Include="xunit" Version="2.6.4" />
+    <PackageReference Include="xunit" Version="2.6.6" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.5.6" />
     <PackageReference Include="Newtonsoft.Json" Version="13.0.3" />
     <PackageReference Include="Nullable" Version="1.3.1" PrivateAssets="All" />

Tests/Tests.csproj

@@ -21,7 +21,7 @@
     <PackageReference Include="Microsoft.CSharp" Version="4.7.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
     <PackageReference Include="Verify.Xunit" Version="22.9.0" />
-    <PackageReference Include="xunit" Version="2.6.4" />
+    <PackageReference Include="xunit" Version="2.6.6" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.5.6" />
     <PackageReference Include="Newtonsoft.Json" Version="13.0.3" />
   </ItemGroup>