DotNet 9 support

[sailro]

Hello there!

Supporting multiple frameworks (net8, net9, ..) for this dotnet tool would be quite convenient.

No need to dual install net8 (for retest) and net9 (for an app) when you want to build and test your net9-only application in your CI.

Happy to create a PR if you want.

Thanks!

[kzu]

Thanks for backing the issue. I think #93 should fix this.

Could you give it a try by installing the tool from the CI feed: dotnet tool update -g dotnet-retest --add-source https://pkg.kzu.app/index.json --prerelease

[sailro]

Indeed it works. Thanks !

[kzu]

Great, shipping it now!