Add a dev container to the repository #102973

Originally discussed at https://discuss.python.org/t/add-support-for-devcontainers-to-facilitate-github-codespaces-usage/21330 , the idea is to get to the point where we can have GitHub Codespaces prebuilds. This would get people a running container in under a minute with CPython and the docs already fully built. The idea is it saves everyone time by having a preconfigured setup, making things like getting started as sprints extremely easy. It can also help in situations like with WASI where the toolchain can come pre-installed to make getting started much easier.

FYI everyone on GitHub gets 120 CPU-hours of free Codespaces, so that means a 2-core CPU instance is worth 60 hours of use. And with prebuilds, at least the initial building of python and the docs comes for "free" for users.

Adding this setup has already been approved by the SC.

Linked PRs

• GH-102973: add a dev container #102975
• GH-102973: Slim down Fedora packages in the dev container #103283