Bump NUnit3TestAdapter from 5.2.0 to 6.0.0 (#931)

---
updated-dependencies:
- dependency-name: NUnit3TestAdapter
  dependency-version: 6.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
- dependency-name: NUnit3TestAdapter
  dependency-version: 6.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

tests/NSubstitute.Acceptance.Specs/NSubstitute.Acceptance.Specs.csproj

@@ -10,7 +10,7 @@
   <ItemGroup>
     <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="10.0.0" />
     <PackageReference Include="NUnit" Version="4.4.0" />
-    <PackageReference Include="NUnit3TestAdapter" Version="5.2.0" />
+    <PackageReference Include="NUnit3TestAdapter" Version="6.0.0" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(TargetFramework)' == 'net462'">