ArtifactClient emits an error instead of uploading symlinks to directories

[p--b]

Describe the bug
If a symlink which points to a directory is passed as one of the files arguments to ArtifactClient.uploadArtifact(), then the following error is raised:

Error: EISDIR: illegal operation on a directory, read
Emitted 'error' event on ReadStream instance at:
    at internal/fs/streams.js:167:12
    at FSReqCallback.wrapper [as oncomplete] (fs.js:470:5) {
  errno: -21,
  code: 'EISDIR',
  syscall: 'read'
}

To Reproduce
Within an action:

1. Create a symlink which points to a directory
2. Attempt to upload it as an artifact
3. Receive the above error

Slightly less literally:

Attempt to use https://github.com/fourieraudio/upload-artifact/tree/no-follow to upload an artifact which contains a symlink to a directory, with the new follow-symlinks variable set to false (see actions/upload-artifact#201)

Expected behavior
A file, which is a symlink, is uploaded as an artifact.

Screenshots
N/A

Desktop (please complete the following information):
GitHub Actions Runner Ubuntu 20.04

Additional context
I was attempting to add support for archiving symlinks so that I could add support to upload-artifact.

I did have a stab at fixing this (see https://github.com/fourieraudio/toolkit/compare/main..symlink ) but I didn't seem to have much joy, and sadly ran out of time to debug this further.