Bump Benchly and BenchmarkDotNet (#639)

Bumps [Benchly](https://github.com/bitfaster/benchly) and [BenchmarkDotNet](https://github.com/dotnet/BenchmarkDotNet). These dependencies needed to be updated together.

Updates `Benchly` from 0.6.1 to 0.7.0
- [Release notes](https://github.com/bitfaster/benchly/releases)
- [Commits](bitfaster/benchly@v0.6.1...v0.7.0)

Updates `BenchmarkDotNet` from 0.14.0 to 0.14.0
- [Release notes](https://github.com/dotnet/BenchmarkDotNet/releases)
- [Commits](dotnet/BenchmarkDotNet@v0.14.0...v0.14.0)

---
updated-dependencies:
- dependency-name: Benchly
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: BenchmarkDotNet
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

BitFaster.Caching.Benchmarks/BitFaster.Caching.Benchmarks.csproj

@@ -19,7 +19,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Benchly" Version="0.6.1" />
+    <PackageReference Include="Benchly" Version="0.7.0" />
     <PackageReference Include="BenchmarkDotNet" Version="0.14.0" />
     <PackageReference Include="BenchmarkDotNet.Diagnostics.Windows" Version="0.14.0" />
     <PackageReference Include="MathNet.Numerics" Version="5.0.0" />