dotnet 9.0 support needed

[hakankutluay]

dotnet build command raises a warning about the version on dotnet 9.0 projects.

error NU1701: Package 'CsvHelper 2.11.0' 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 'net9.0'. This package may not be fully compatible with your project.

Adding net9.0 support will fix that warning.

[Rob-Hague]

Version 2.11 is 10 years old. Any recent version (for at least the last 5 years) is compatible with .NET 9 and does not need an explicit net9.0 target

[hakankutluay]

you are right @Rob-Hague , somehow the older version has been added to proj, that's why getting the warning.

having that target still has no side affect. so will close the issue, but having PR still make sense. wdyt?