`data` subfolder not part of package manifest?

I am trying to make a standalone executable of my [Meta Package Manager](https://github.com/kdeldycke/meta-package-manager) project, which depends on [`cyclonedx-python-lib`](https://github.com/CycloneDX/cyclonedx-python-lib) for SBOM export, itself depending on `license-expression`.

For this I use [Nuitka](https://github.com/Nuitka/Nuitka) which worked well up until I introduced a dependency on `license-expression`.

Nuitka complains of missing `data/scancode-licensedb-index.json` file. I reported this issue upstream and proposed a fix so that Nuitka can automatically embed the missing file: https://github.com/Nuitka/Nuitka/pull/3033

That being said, Nuitka is generally capable of guessing which data file to include, if the Python module has been properly built and declared in package metadata. Which probably means the `data` subfolder has not been part of the manifest.