Bug: Issue installing new kernel from main

While I was able to install the ipykernel from main, when I tried to make a new kernel I ran into the following error:
```
.venv/lib64/python3.11/site-packages/ipykernel/kernelapp.py", line 734, in main
if self.kernel.eventloop:
^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'eventloop'
```

Manually creating a kernel worked fine

Reproduce the failure by installing ipykernel from main and creating a new kernel, then inspect .venv/lib64/python3.11/site-packages/ipykernel/kernelapp.py around line 734. Compare this path with the manually created kernel case; done means new-kernel creation no longer raises the reported AttributeError.

Rédigé par le modèle d'indexation à partir du texte de l'issue.