if working with a directory, do not download the whole thing

[deitch]

The github-sbom-generator currently figures out the download URL based on the passed arg, either a URL like https://github.com/foo/bar#commit or a path. In the case of a URL, it obviously has to download it to scan for license files. But in the case of a path, it doesn't need to download it, since it already is there. Yet it is generating the download URL and then downloading and scanning.

This PR changes it so that if it is a directory, it scans for the license files in the directory rather than downloading them.

This makes it much faster, especially for big repos, like eve-kernel.

cc @rucoder @eriknordmark

[deitch]

@eriknordmark I do not understand enough about the codeql setup to know what it is complaining about. Do you?

[eriknordmark]

@eriknordmark I do not understand enough about the codeql setup to know what it is complaining about. Do you?

No and I have to compare the codeql setup for this repo with other ones to figure out what I did differently when I enabled it.

[eriknordmark]

LGTM