Fix Data related Warning

[martinrohbeck]

Running

# Afterwards, we need to add the data
model.add_data(data=mdata)

raises
/home/m015k/code/cellij/cellij/core/_factormodel.py:251: FutureWarning: Passing 'suffixes' which cause duplicate columns {'T6_x', 'T5_x', 'treatedAfter_x', 'Gender_x', 'IGHV_x', 'Diagnosis_x', 'ConsClust_x', 'died_x', 'IC50beforeTreatment_x', 'Age4Main_x'} in the result is deprecated and will raise a MergeError in a future version.

coming from some suffixes. See code line

cellij/cellij/core/_factormodel.py

Line 251 in a0385d7

anndata_object.obs = anndata_object.obs.merge(