hooks: add uvicorn

[imba-tjd]

I have seen pyinstaller/pyinstaller#4664
But I think it's OK to include the whole uvicorn, because it's pure Python.

[bwoodsend]

Ughh I hate libraries that do this. Having both dynamical imports and optional dependencies means that we simultaneously must and must not use collect_submodules(). And our tests will always be either hopelessly inadequate in that they provide almost zero coverage or have to brute force iterate through all the permutations and take hours like our scikit-image tests.

[bwoodsend]

Thanks @imba-tjd.