Bump BenchmarkDotNet from 0.13.8 to 0.13.9

Bumps [BenchmarkDotNet](https://github.com/dotnet/BenchmarkDotNet) from 0.13.8 to 0.13.9.
- [Release notes](https://github.com/dotnet/BenchmarkDotNet/releases)
- [Commits](dotnet/BenchmarkDotNet@v0.13.8...v0.13.9)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

tests/LinkDotNet.StringBuilder.Benchmarks/LinkDotNet.StringBuilder.Benchmarks.csproj

@@ -9,7 +9,7 @@
     </PropertyGroup>
 
     <ItemGroup>
-      <PackageReference Include="BenchmarkDotNet" Version="0.13.8" />
+      <PackageReference Include="BenchmarkDotNet" Version="0.13.9" />
     </ItemGroup>
 
     <ItemGroup>