Update Docker image + fix MSYS compilation

Currently, compilation does not work on the latest devkitPro Docker images, which also means there will be significant issues when self-compiling. I'd like to find the latest Docker image that does work (edit: it's 20231110, which we're already on!) and then fix issues as they pop up with each new version.

This is also a blocker for MSYS CI building: it does not use a Docker image; instead, it downloads devkitPro pacman and all the necessary dependencies at their latest versions.