[CI] - re-enable unitary_compilation_diffusion_models.ipynb

[mitchdz]

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Describe the bug

#4466 disabled the jupyter notebook due to flaky issues. Investigate the actual failure and re-enable the notebook.

Steps to reproduce the bug

CI

Expected behavior

No time out

Is this a regression? If it is, put the last known working version (or commit) here.

Not a regression

Environment

CI

Suggestions

No response