Bump BenchmarkDotNet from 0.14.0 to 0.15.6#12

dependabot[bot] wants to merge 1 commit intomasterl2-hacker3bmn/NaCl.Core:masterfrom

dependabot/nuget/test/NaCl.Core.Benchmarks/BenchmarkDotNet-0.15.6l2-hacker3bmn/NaCl.Core:dependabot/nuget/test/NaCl.Core.Benchmarks/BenchmarkDotNet-0.15.6Copy head branch name to clipboard