check reuse compliant licenses as well, to omit having a second license file

[maurerle]

I'd like to track a downstream issue here, which occurs when submitting a paper to JOSS from a repository with only reuse licenses:

From the REUSE 3.3 Spec

Each License File MUST be placed in the LICENSES/ directory in the root of the Project.
...
You MAY include COPYING or LICENSE files in your project for compliance with other standards, conventions, or tools. These files MAY contain a copy of the license text, a summary of your licensing, or anything else. These files are ignored by the REUSE Tool.

Of course the solution has to be done in licensee which is used to determine the license and already has an upstream issue:
licensee/licensee#737

Workaround

For now the only way to correctly submit a paper to JOSS is to add a redundent LICENSE file to the repository.

Reference JOSS papers:
openjournals/joss-reviews#7666
openjournals/joss-reviews#5041