Bump Grpc.Core from 2.43.0 to 2.46.6

Bumps [Grpc.Core](https://github.com/grpc/grpc) from 2.43.0 to 2.46.6.
- [Release notes](https://github.com/grpc/grpc/releases)
- [Changelog](https://github.com/grpc/grpc/blob/master/doc/grpc_release_schedule.md)
- [Commits](https://github.com/grpc/grpc/commits)

---
updated-dependencies:
- dependency-name: Grpc.Core
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

NineChronicles.Headless.Executable.Tests/NineChronicles.Headless.Executable.Tests.csproj

@@ -11,7 +11,7 @@
     </PropertyGroup>
 
     <ItemGroup>
-        <PackageReference Include="Grpc.Core" Version="2.43.0" />
+        <PackageReference Include="Grpc.Core" Version="2.46.6" />
         <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.1.0" />
         <PackageReference Include="xunit" Version="2.4.0" />
         <PackageReference Include="xunit.runner.visualstudio" Version="2.4.0" />