Licensing of test data

Does anyone know what the copyright status and the licensing terms of
the digikam test data are?  And could those be added to the repository
somewhere?

(my apologies if this is documented somewhere, and I overlooked it)

for context: I packaged digikam for Guix (a distro, package manager,
config manager, etc), and before submitting it to the package repository
I need to know the license under which the test data is distributed.

Kind regards,
pinoaffe