Bump xunit.runner.visualstudio from 3.1.5 to 4.0.0

---
updated-dependencies:
- dependency-name: xunit.runner.visualstudio
  dependency-version: 4.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

src/OpenOnlineConfig.Tests/OpenOnlineConfig.Tests.csproj

@@ -11,7 +11,7 @@
   <ItemGroup>
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.9.0" />
     <PackageReference Include="xunit" Version="2.9.3" />
-    <PackageReference Include="xunit.runner.visualstudio" Version="3.1.5">
+    <PackageReference Include="xunit.runner.visualstudio" Version="4.0.0">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>