I could solve the error by using image python:3.11.9-bookworm, since gcc was missing in the slim image (would be good to have some guideline to which minimum requirements a Docker image should have?).

Now, I am stuck with an error which seems to be related to poetry and pip, and their interplay. Poetry installs my own project, which is then listed as a requirement for pip, which does not find it on the PyPI server (obviously) and complains that it can't install it. I run the pipeline in services mode in a Docker container, and the regular tasks in normal mode in a virtualenv on my machine. The logs follow: