Bump Grpc.Net.Client from 2.65.0 to 2.66.0 in /dotnet-etcd

Bumps [Grpc.Net.Client](https://github.com/grpc/grpc-dotnet) from 2.65.0 to 2.66.0.
- [Release notes](https://github.com/grpc/grpc-dotnet/releases)
- [Changelog](https://github.com/grpc/grpc-dotnet/blob/master/doc/release_process.md)
- [Commits](grpc/grpc-dotnet@v2.65.0...v2.66.0)

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

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

dotnet-etcd/dotnet-etcd.csproj

@@ -49,7 +49,7 @@ Advanced uses take advantage of the consistency guarantees to implement database
   <ItemGroup>
     <PackageReference Include="Google.Api.CommonProtos" Version="2.15.0" />
     <PackageReference Include="Google.Protobuf" Version="3.27.3" />
-    <PackageReference Include="Grpc.Net.Client" Version="2.65.0" />
+    <PackageReference Include="Grpc.Net.Client" Version="2.66.0" />
     <PackageReference Include="Grpc.Tools" Version="2.65.0">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>