Describe the bug
Impossible to create de DeseqDataSet object with this version. This problem occurs even with the loaded_example_data

To Reproduce
inference = DefaultInference(n_cpus=8)
dds = DeseqDataSet(
counts=counts_df,
metadata=metadata,
design_factors="Condition",
refit_cooks=True,
inference=inference,
# n_cpus=8, # n_cpus can be specified here or in the inference object
)

Expected behavior
Generation of the DeseqDataset dds object

Additional context

KeyError Traceback (most recent call last)
Cell In[279], line 2
1 inference = DefaultInference(n_cpus=8)
----> 2 dds = DeseqDataSet(
3 counts=counts_df,
4 metadata=metadata,
5 design_factors="Condition",
6 refit_cooks=True,
7 inference=inference,
8 # n_cpus=8, # n_cpus can be specified here or in the inference object
9 )

File ~/miniconda3/envs/rnaseq/lib/python3.10/site-packages/pydeseq2/dds.py:216, in DeseqDataSet.init(self, adata, counts, metadata, design_factors, continuous_factors, ref_level, min_mu, min_disp, max_disp, refit_cooks, min_replicates, beta_tol, inference, quiet)
211 self.design_factors = (
212 [design_factors] if isinstance(design_factors, str) else design_factors
213 )
214 self.continuous_factors = continuous_factors
--> 216 if self.obs[self.design_factors].isna().any().any():
217 raise ValueError("NaNs are not allowed in the design factors.")
218 self.obs[self.design_factors] = self.obs[self.design_factors].astype(str)

File ~/miniconda3/envs/rnaseq/lib/python3.10/site-packages/pandas/core/frame.py:4096, in DataFrame.getitem(self, key)
4094 if is_iterator(key):
4095 key = list(key)
...
-> 6248 raise KeyError(f"None of [{key}] are in the [{axis_name}]")
6250 not_found = list(ensure_index(key)[missing_mask.nonzero()[0]].unique())
6251 raise KeyError(f"{not_found} not in index")

KeyError: "None of [Index(['Condition'], dtype='object')] are in the [columns]"