enable python dependency scanning to work when source dists are not included

The latest dependency scanning container added some build packages that will only be useful if the Pypi repo being pointed at has the source dists in it. For example, it won’t work for things requiring SQL libs (e.g. mysql, postresql, etc).

For security reasons some customers do not include source dist as they do not want people rebuilding the binaries that have already been built. It would be using something that isn't being shipped, if you ship binaries.

As a result the user would like to enable dependency scanning to work without included source dists