Hotfix for failing `np.`-like data operations

... these actually require a keyword-only argument! D'uh.

Can this MR be accepted?

• Implementation ready

• Code quality
  • Changes follow coding guidelines
  • Checked code coverage on new and adjusted code

• Ready for merging
  • Pipeline passes without warnings
  • History cleaned-up or squash option set
  • Changelog entry added
  • Version number bumped