Add support for NET 8.0

[RomanLeonB]

Describe the problem to solve
I want to add NLog.Targets.Syslog to a NET 8.0 application

Describe the enhancement proposed
Upgrade *.csproj to NET 8.0

I can also upgrade the *.csproj files if that's okay with you.

[snakefoot]

Maybe just remove net6.0 and just rely on netstandard2.0 ?

[RomanLeonB]

I think this is not possible, because TestAppWithGU and TestAppWithTUI does explicitly use net6.0 or net6.0-windows
Or do you mean to set all targets to netstandard2.0?

My suggestion:
Remove net6.0 support in FakeSyslogServer
Remove net6.0 support in NLog.Targets.Syslog.Schema
Remove net6.0 support in NLog.Targets.Syslog
Upgrade TestAppWithGUI to net8.0
Upgrade TestAppWithTUI to net8.0

[RomanLeonB]

Maybe just remove net6.0 and just rely on netstandard2.0 ?

I may have been too hasty with my solution. Do you agree with my suggestion so that I can create a PR afterwards?

[jasells]

@RomanLeonB What is the status with this? I have an open issue that may be partially addressed, if retargeted to .netstandard2.0? Generally, I think this is the best option for a lib like this vs. a specific .net Core version target, unless there's something the lib just absolutely needs from .Net Core (6/7/8...).

I certainly would prefer to build on any changes made for .netstandard2.0, and avoid a fork? Glad to see some activity here.

A quick hack on a local copy appears to build fine with only .netstandard2.0 targets for the lib projects, as you suggested, and as I would expect.

It must work, right? 😉

[jasells]

@RomanLeonB you should be able to just consume this .Net6/standard package in a .Net8 app or lib without changing this lib's target.

That said, IMHO, it would simplify maintenance of this lib to remove .Net6, and just target .netstandard since standard has no sunset of support. .netstandard support policy: https://learn.microsoft.com/en-us/dotnet/standard/net-standard?tabs=net-standard-1-0#net-5-and-net-standard

It also makes the packages a tad smaller since it only contains a single .dll at that point.