MAINT: Bump CircleCI Python version

[larsoner]

No description provided.

[larsoner]

Hoping this will magically fix the CircleCI failure observed in #70 but who knows

[larsoner]

@mgeier can you add me to the spatialaudio org? That way I can follow https://discuss.circleci.com/t/git-ghproxy-9d2.pages.dev-permission-denied-publickey-on-repo-that-previously-worked/37763/4

You can also take the steps if you want but the next time this happens (if ever) you'll have to do it again. Up to you...

[larsoner]

(I already clicked the "stop building" button, I just need to be part of the org on GitHub to be able to join the org on CircleCI to add the project back!)

[mgeier]

You have admin rights in this project, but I'm not allowed to give you full access to the whole organization.

However, I could move the project to a different organization where we would have more flexibility.