deps: Bump BenchmarkDotNet from 0.14.0 to 0.15.6 (#490)

---
updated-dependencies:
- dependency-name: BenchmarkDotNet
  dependency-version: 0.15.6
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Franklin Moormann <[email protected]>

Author: dependabot[bot]

tests/AiDotNet.Tests/AiDotNetTests.csproj

@@ -23,7 +23,7 @@
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>
-    <PackageReference Include="BenchmarkDotNet" Version="0.14.0" />
+    <PackageReference Include="BenchmarkDotNet" Version="0.15.6" />
   </ItemGroup>
 
   <ItemGroup>