Using PowerAssert with .Net 8 leads to warnings

[Danyyer]

Because of the netcoreapp1.1 reference the Libuv package is restored which triggers the following warning when compiling with .Net 8:

dotnet\sdk\8.0.100\Sdks\Microsoft.NET.Sdk\targets\Microsoft.NET.Sdk.targets(284,5): warning NETSDK1206: Found version-sp
ecific or distribution-specific runtime identifier(s): debian-x64, fedora-x64, opensuse-x64, rhel-x64, win7-arm, win7-x64, win7-x86. Affe
cted libraries: Libuv. In .NET 8.0 and higher, assets for version-specific and distribution-specific runtime identifiers will not be foun 
d by default. See https://aka.ms/dotnet/rid-usage for details. 

Proposal:
Add net8.0 to Target Frameworks.