fix: quartonotebook imported over multiple lines which broke detect-nf-test-changes

[adamrtalbot]

See https://github.com/nf-core/modules/actions/runs/11974423411/job/33385468168 for an example of a broken test caused by this change.

This reverts the multi-line import introduced in #5561

We need to fix the detect-nf-test but for now this will keep us going.

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