Updated TargetFrameworkMoniker from 4.0 to 4.8

[r-pankevicius]

A poor fix for #752

[r-pankevicius]

No idea why .net 5 is used to build the merge request.

C:\Program Files\dotnet\sdk\5.0.416\Sdks\Microsoft.NET.Sdk\targets\Microsoft.NET.TargetFrameworkInference.targets(141,5):

error NETSDK1045: The current .NET SDK does not support targeting .NET 6.0.  Either target .NET 5.0 or lower, or use a version of the .NET SDK that supports .NET 6.0. [C:\projects\electron-net\ElectronNET.API\ElectronNET.API.csproj]

[FlorianRappl]

No idea why .net 5 is used to build the merge request.

I would not worry about it. We are in process to migrate away from AppVeyor to GitHub actions using NUKE.

[FlorianRappl]

Part of #757.