Ability to build the solution on Linux

[sandrock]

This configuration (firefly) fails to build the solution

"/home/sandrock/dev/github/sandrock/srktoolkit-v2/Sources/SrkToolkit.Common/SrkToolkit.Common.csproj" (build target) (2) ->
(GetReferenceAssemblyPaths target) -> 
/usr/lib/mono/msbuild/Current/bin/Microsoft.Common.CurrentVersion.targets(1232,5): error MSB3971: The reference assemblies for ".NETFramework,Version=v7.0" were not found. You might be using an older .NET SDK to target .NET 5.0 or higher. Update Visual Studio and/or your .NET SDK.

"/home/sandrock/dev/github/sandrock/srktoolkit-v2/Sources/SrkToolkit.Domain/SrkToolkit.Domain.csproj" (build target) (1:2) ->
/usr/lib/mono/msbuild/Current/bin/Microsoft.Common.CurrentVersion.targets(1232,5): error MSB3971: The reference assemblies for ".NETFramework,Version=v7.0" were not found. You might be using an older .NET SDK to target .NET 5.0 or higher. Update Visual Studio and/or your .NET SDK.

"/home/sandrock/dev/github/sandrock/srktoolkit-v2/Sources/SrkToolkit.Common/SrkToolkit.Common.csproj" (build target) (2:2) ->
(ResolvePackageAssets target) -> 
/usr/lib/mono/msbuild/Current/bin/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(241,5): error NETSDK1005: Assets file '/home/sandrock/dev/github/sandrock/srktoolkit-v2/Sources/SrkToolkit.Common/obj/project.assets.json' doesn't have a target for '.NETFramework,Version=v4.7.2'. Ensure that restore has run and that you have included 'net472' in the TargetFrameworks for your project.

dotnet sdk check
.NET SDKs:
Version      Status
----------------------------------------
2.2.207      .NET 2.2 is out of support.
3.1.120      .NET 3.1 is out of support.
6.0.113      Patch 6.0.115 is available.
7.0.102      Patch 7.0.104 is available.

Try out the newest .NET SDK features with .NET 8.0.100-preview.2.23157.25.

.NET Runtimes:
Name                          Version      Status
----------------------------------------------------------------------
Microsoft.NETCore.App         2.2.8        .NET 2.2 is out of support.
Microsoft.NETCore.App         3.1.20       .NET 3.1 is out of support.
Microsoft.NETCore.App         6.0.13       Patch 6.0.15 is available.
Microsoft.AspNetCore.App      7.0.2        Patch 7.0.4 is available.
Microsoft.NETCore.App         7.0.2        Patch 7.0.4 is available.