"Work package" is a pretty universal term in non-software project management, though a single WP could contain multiple todo items. I'm not sure whether it was coined by one of the frameworks like PRINCE2, but a lot of large/governmental systems use it (certainly the UK/Innovate, NASA and ESA, etc).

I would interpret "issue" as more of a general "thing that needs doing" whereas work package has a fairly specific meaning. I wouldn't want to use the phrase work packages as items in a bug tracker, for example.

See:

- https://prince2.wiki/management-products/work-package/ - https://www.nasa.gov/wp-content/uploads/2023/08/nasa-work-br... (pdf)