Investigate if we need to have drupal/core as an explicit dependency

Asked the question in Drupal Slack's contribute channel:
https://drupal.slack.com/archives/C1BMUQ9U6/p1739367786307179

Readin the discussion there, it is suggested to keep both, however it would be good to add a test to keep them in sync.

This test won't work because of the way gitlab pipelines work, closing this issue.