Enable linux docker builds on Apple Silicon

[i]

Currently the output from pip install pedalboard when run from a linux-based docker container running on an Apple Silicon host returns the following error:

ERROR: Could not find a version that satisfies the requirement pedalboard (from versions: none)

This change should fix that error. Please verify this works because I wasn't able to test (not having access to the github actions runner, etc).

[psobot]

Thanks @i! I think this will likely disable the non-aarch64 architectures on Linux - the cibuildwheel documentation suggests adding another step to the GitHub Action job, as well as keeping auto in the list of architectures:

# On an Linux Intel runner with qemu installed, build Intel and ARM wheels
CIBW_ARCHS_LINUX: "auto aarch64"

[psobot]

Thanks for kicking this off, @i!