Fix package reference, PrivateAssets is needed

Source/Apos.Input.csproj

@@ -23,7 +23,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="MonoGame.Framework.DesktopGL" Version="3.8.0.1641" />
+    <PackageReference Include="MonoGame.Framework.DesktopGL" PrivateAssets="All" Version="3.8.0.1641" />
   </ItemGroup>
 
   <ItemGroup>