LibGit2Sharp should target netstandard

[aaronpburke]

PR 2026 changed the lib from targeting netstandard2.0 to net6.0 and netframework472. What was the rationale behind this decision? This means I'm unable to include LibGit2Sharp in my netstandard2.0 library's package references without it throwing a warning.

Targeting netstandard2.0 will encompass netframework472, net6, and net7.

Reproduction steps

Create a netstandard2.0 library project with <PackageReference Include="LibGit2Sharp" Version="0.27.2" />

Expected behavior

Library compiles without warnings.

Actual behavior

Upon building my netstandard2.0 library which references LibGit2Sharp, I receive the following warning:

warning NU1701: Package 'LibGit2Sharp 0.27.2' was restored using '.NETFramework,Version=v4.6.1, .NETFramework,Version=v4.6.2, .NETFramework,Version=v4.7, .NETFramework,Version=v4.7.1, .NETFramework,Version=v4.7.2, .NETFramework,Version=v4.8, .NETFramework,Version=v4.8.1' instead of the project target framework '.NETStandard,Version=v2.0'. This package may not be fully compatible with your project.

Version of LibGit2Sharp (release number or SHA1)

0.27.2

Operating system(s) tested; .NET runtime tested

Ubuntu-20.04, .NET 6 app which links to netstandard2.0 library; netstandard2.0 library links to LibGit2Sharp.