Do not check for binary artifacts for data projects

If the project requested to be installed is a data package, the logic introduced in !426 (merged) is not applicable and results in the spurious error reported in #127 (closed).

This MR is a workaround for the issue (a proper fix is not really possible without a major refactoring of the system).

Closes #127 (closed)

/cc @cburr

changed milestone to %4.0.8

approved this merge request

merged

mentioned in commit 7feba1c5

mentioned in merge request !431 (merged)