MINOR: [C#] Bump Grpc.Net.Client from 2.65.0 to 2.71.0#53

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dependabot/nuget/csharp/src/Apache.Arrow.Flight/Grpc.Net.Client-2.71.0QuietCraftsmanship/arrow:dependabot/nuget/csharp/src/Apache.Arrow.Flight/Grpc.Net.Client-2.71.0Copy head branch name to clipboard