NuGet package target framework with no libs causes cache manifest validation to fail and redownload the plugin on every game launch

[StarCpt]

Pulsar/Shared/Network/NuGetPackage.cs

Lines 44 to 62 in 206584e

	NuGetFramework nearest = frameworkReducer.GetNearest(
	targetFramework,
	itemGroups.Select(x => x.TargetFramework)
	);
	if (nearest is not null)
	{
	List<Item> libFiles = [];
	foreach (
	FrameworkSpecificGroup group in itemGroups.Where(x =>
	x.TargetFramework.Equals(nearest)
	)
	)
	libFiles.AddRange(
	group
	.Items.Select(x => GetPackageItem(x, group.TargetFramework, contentItems))
	.Where(x => x is not null)
	);
	return [.. libFiles];
	}

For example, the .net framework 4.5 library directory in System.Reflection.Emit.Lightweight is a stub. Pulsar should check FrameworkSpecificGroup.HasEmptyFolder to exclude stub frameworks.

[StarCpt]

My bad, this is incorrect. net45 target contains no libs because it is part of mscorlib. However it still causes a bug where the cache manifest is assumed to be invalid because the plugin contains packages but no lib asset files are listed in the manifest. This breaks the cache so plugins are re-downloaded and compiled on every game launch.