Thanks a lot, and Happy New Year to you too 
That鈥檚 strange. Did you try to uninstall diffusers first? If you didn鈥檛, you can use pip uninstall -y diffusers and then issue the install command again, just to verify there鈥檚 nothing weird going on.
If that doesn鈥檛 work, you can also run diffusers-cli env and post the output here so I can try to replicate in a similar environment. Are you running the notebook on Colab or somewhere else?
I hope we can sort this out