Reduce installation requirements

[gvalkov]

The azure dependencies don't seem to be used anywhere or at least I can't find any references. Pygmentize and wheel are also only needed during development. Pygments can probably be just pulled through Sphinx ... don't know what is gained by pinning it here.

This removes ~175MB from the installation size (not accounting for any overlap with the other installation dependencies).

$ python3 -m pip install -t . azure-mgmt-compute==27.2.0 azure-mgmt-storage==20.0.0 azure-mgmt-resource==21.1.0 azure-storage-blob==12.12.0 azure-keyvault-secrets==4.4.0 pygments==2.12.0 wheel==0.37.1
$ du -hs
175MB