BREAKING: Dedupe tokens: color, font-size, line-height, duration

[bartveneman]

What

When using this library to generate tokens for any meaningful work you quickly run into issues where it's useless to have 2 different color tokens for #f00 and rgb(255 0 0). We're now deduplicating the following token types because they can be easily normalized:

• color
• font-size
• line-height
• duration

Breaking changes

1. Hash values have changed
2. Many values are deduplicated: where you previously expect red and #f00 to turn up as individual items they're now merged into one
3. Required Node version changed from 18 to 22 (primarily to facilitate modern JS features like Set.union()

closes #27