Add Adam Turner as the default reviewer for PEP infrastructure

[AA-Turner]

I'll regret this!
A

[JelleZijlstra]

Thank you!

[AA-Turner]

First PR merged, too! 🎉

[CAM-Gerlach]

Great! A few other things you might want to consider also claiming, in case you haven't already:

• /docs (co-claim with me, if desired; at least until we decide what to do with them)
• /.github/workflows (I can co-claim as well)
• Makefile (since your work has considerable effect on this)
• requirements.txt (you'll likely want to know when deps are changed)

I will propose to claim .pre-commit-config.yml, since I wrote most of it in its current form (along with Hugo) and I'm pretty intimately familiar with pre-commit.

[AA-Turner]

Done apart from /docs (in case we remove all docs, don't want needless churn)
A

[CAM-Gerlach]

Thanks!