Minimum/maximum supported dotnet version for sharp

[spencerpogo]

I have found that sharp builds successfully on dotnet 5.0, which is EOL. On 6.0, the current LTS, the build fails with the following errors:

       > /build/source/sharp/Olympus.Sharp.csproj : error NU1102: Unable to find package Microsoft.NETFramework.ReferenceAssemblies with version (>= 1.0.2)
       > /build/source/sharp/Olympus.Sharp.csproj : error NU1102:   - Found 1 version(s) in nugetSource [ Nearest version: 1.0.0 ]

I'm not that much of a dotnet person, but the csproj mentions requiring net452, which I assume is dotnet 4.5.2. Is this the current state of affairs or am I just doing something wrong? I had to put in some extra work to support 5.0 as it is EOL and has been removed from nixpkgs.