Get back net6 support

[gorsheninmv]

.NET6 support is valid until November 12, 2024, more than half a year, I'm not sure this is a good idea to abandon .NET6 support in Electron.NET.

I would like to suggest making the project multitarget and support both LTS versions (.NET6 and .NET8)

dotnet tool doesn't support self-contaied tools (see dotnet/sdk#9565), so that <PublishSelfContained>true</PublishSelfContained> can be useful only for binaries but not for dotnet tool so I decided to remove the line

[FlorianRappl]

In general the multi target approach works for me - just not sure about the execution in there.

What we'd need is that the published NuGet package contains both frameworks; still the dotnet commands are run with an explicit framework derived from the ElectronNET.WebApp project.

Just wondering if this is achieved here; maybe only the contained tools is then .NET 8, but the libs contains both.

[gorsheninmv]

The structure of CLI dotnet tool package I got after executing dotnet pack

.
|   ElectronNET.CLI.nuspec
|   PackageIcon.png
|   [Content_Types].xml
|   
+---package
|   \---services
|       \---metadata
|           \---core-properties
|                   553c89be248c4da09d1469f93f9abb2f.psmdcp
|                   
+---tools
|   +---net6.0
|   |   \---any
|   |           dotnet-electronize.deps.json
|   |           dotnet-electronize.dll
|   |           dotnet-electronize.pdb
|   |           dotnet-electronize.runtimeconfig.json
|   |           DotnetToolSettings.xml
|   |           
|   \---net8.0
|       \---any
|               dotnet-electronize.deps.json
|               dotnet-electronize.dll
|               dotnet-electronize.pdb
|               dotnet-electronize.runtimeconfig.json
|               DotnetToolSettings.xml
|               
\---_rels
        .rels

The structure of API package I got after executing dotnet pack

.
|   ElectronNET.API.nuspec
|   PackageIcon.png
|   [Content_Types].xml
|   
+---lib
|   +---net6.0
|   |       ElectronNET.API.dll
|   |       ElectronNET.API.xml
|   |       
|   \---net8.0
|           ElectronNET.API.dll
|           ElectronNET.API.xml
|           
+---package
|   \---services
|       \---metadata
|           \---core-properties
|                   3528134964fe4b75b8c25a49aef2d054.psmdcp
|                   
\---_rels
        .rels

I double checked if the packages worked correctly with my .NET6 app and .NET8 demo webapp.
Let me know if I should check something else.

[FlorianRappl]

No structure looks fine to me!

Let's keep it like that - thanks for checking!