For cibuildwheels, requirements must be specified as follows in pyproject.toml:

Build:

requires = ["scikit-build-core >=0.10", "nanobind >=1.3.2"]

Test:

test-requires = ["numpy", "compas", "pytest", "build", "tessagon"]

Since tessagon is only used in testing, it is enough to specify it in test-requires list.

This building process is different from the local build, that is why requirements.txt were not working.
In total we are building twice:

1. one time on a local os on one single python version
2. second time on cibuildwheels for all python versions