chore: Bump Microsoft.NET.Test.Sdk from 18.5.1 to 18.8.1

---
updated-dependencies:
- dependency-name: Microsoft.NET.Test.Sdk
  dependency-version: 18.8.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

tests/Auth0.AspNetCore.Authentication.Api.UnitTests/Auth0.AspNetCore.Authentication.Api.UnitTests.csproj

@@ -12,7 +12,7 @@
     <ItemGroup>
         <!-- Using v7.2.1 as it's the last version with Apache license. Newer versions use different licensing -->
         <PackageReference Include="FluentAssertions" Version="7.2.2"/>
-        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.5.1"/>
+        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.8.1"/>
         <PackageReference Include="Moq" Version="4.20.72"/>
         <PackageReference Include="xunit" Version="2.9.3"/>
         <PackageReference Include="xunit.runner.visualstudio" Version="3.1.5">