diffexpr (DEseq2 wrapper for python) version issue

This is a reference to the restriction of the diffexpr version as introduced here:
https://gitlab.gwdg.de/loosolab/software/loosolab_sc_rna_framework/-/blob/567642a58d92af15159ce698feb891ae3c458ea5/setup.py#L9-10

The issue is that the newer commits of diffexpr includes a pyproject.toml file with very strict dependency settings (https://github.com/wckdouglas/diffexpr/blob/master/pyproject.toml):

This breaks in our current environment. It is possible to install without dependencies using:
pip install git+https://github.com/wckdouglas/diffexpr.git --no-deps but --no-deps cannot be given in setup.py.

The restriction works for now, but it should ideally be fixed by either contacting the package author or making diffexpr installation optional.