chore(main): release 12.4.0

[mljs-bot]

:robot: I have created a release beep boop

12.4.0 (2023-05-05)

Features

• expoe in package.json the different folders (cb0025b)
• expose xCostMatrix (dccc9ba)

Bug Fixes

• correct eslint problems (f631198)

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[mljs-bot]

:robot: Release is at https://github.com/mljs/spectra-processing/releases/tag/v12.4.0 :sunflower: