Bump BenchmarkDotNet from 0.10.2 to 0.12.1

Bumps [BenchmarkDotNet](https://github.com/dotnet/BenchmarkDotNet) from 0.10.2 to 0.12.1.
- [Release notes](https://github.com/dotnet/BenchmarkDotNet/releases)
- [Commits](dotnet/BenchmarkDotNet@v0.10.2...v0.12.1)

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

Author: dependabot-preview[bot]

benchmarks/NBench.Microbenchmarks/NBench.Microbenchmarks.csproj

@@ -9,6 +9,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="BenchmarkDotNet" Version="0.10.2" />
+    <PackageReference Include="BenchmarkDotNet" Version="0.12.1" />
   </ItemGroup>
 </Project>