Bump BenchmarkDotNet from 0.13.1 to 0.15.8 - #12

Node.js 20 actions are deprecated. The following actions are running on Node.js 20 and may not work as expected: actions/checkout@v4, actions/setup-dotnet@v4. Actions will be forced to run with Node.js 24 by default starting June 2nd, 2026. Node.js 20 will be removed from the runner on September 16th, 2026. Please check if updated versions of these actions are available that support Node.js 24. To opt into Node.js 24 now, set the FORCE_JAVASCRIPT_ACTIONS_TO_NODE24=true environment variable on the runner or in your workflow file. Once Node.js 24 becomes the default, you can temporarily opt out by setting ACTIONS_ALLOW_USE_UNSECURE_NODE_VERSION=true. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

Non-nullable property 'Content' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable.

Non-nullable field 'Body' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the field as nullable.

Non-nullable property 'Language' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable.

Possible null reference argument for parameter 'fileName' in 'FileInfo.FileInfo(string fileName)'.

Nullability of reference types in type of parameter 'y' of 'bool LanguageEqualityComparer.Equals(ProgrammingLanguage x, ProgrammingLanguage y)' doesn't match implicitly implemented member 'bool IEqualityComparer<ProgrammingLanguage>.Equals(ProgrammingLanguage? x, ProgrammingLanguage? y)' (possibly because of nullability attributes).

Nullability of reference types in type of parameter 'x' of 'bool LanguageEqualityComparer.Equals(ProgrammingLanguage x, ProgrammingLanguage y)' doesn't match implicitly implemented member 'bool IEqualityComparer<ProgrammingLanguage>.Equals(ProgrammingLanguage? x, ProgrammingLanguage? y)' (possibly because of nullability attributes).

The target framework 'net6.0' is out of support and will not receive security updates in the future. Please refer to https://aka.ms/dotnet-core-support for more information about the support policy.

The target framework 'net6.0' is out of support and will not receive security updates in the future. Please refer to https://aka.ms/dotnet-core-support for more information about the support policy.

The target framework 'net6.0' is out of support and will not receive security updates in the future. Please refer to https://aka.ms/dotnet-core-support for more information about the support policy.

The target framework 'net6.0' is out of support and will not receive security updates in the future. Please refer to https://aka.ms/dotnet-core-support for more information about the support policy.

The target framework 'net6.0' is out of support and will not receive security updates in the future. Please refer to https://aka.ms/dotnet-core-support for more information about the support policy.

The target framework 'net6.0' is out of support and will not receive security updates in the future. Please refer to https://aka.ms/dotnet-core-support for more information about the support policy.

The target framework 'net6.0' is out of support and will not receive security updates in the future. Please refer to https://aka.ms/dotnet-core-support for more information about the support policy.