Provide symbol packages (.snupkg) for Kerberos.NET and related NuGet packages

[petrsnd]

Is your feature request related to a problem? Please describe.
I love being able to build on top of Kerberos.NET by simply adding a NuGet package to my project, but if I run into a Kerberos error related to the way I'm using the library, I can't debug down into Kerberos.NET code to see what I'm doing wrong.

Describe the solution you'd like
I would love to have .snupkg symbol packages for Kerberos.NET and Kerberos.NET.PortableDns so that I can walk through the code in the debugger and see where I have maybe not supplied the right configuration or parameters in using the library.

Describe alternatives you've considered
My workaround for now has been to write a quick test application project directly in the Kerberos.NET source where I have cloned the repository. This works well, but takes time and could potentially go awry if my quick test application doesn't represent my main project well.

Additional context
Maybe debug symbols are available another way that I'm not aware of.

[SteveSyfuhs]

This is likely because it migrated to GitHub actions. Good idea for sure.