fix: remove duplicate license field in dist package.json

[r-portas]

Thanks for the amazing library!

I found a minor bug causing the license field to be duplicated in the dist package.json, which causes a warning when consuming the library within a Bun app:

$ bun --hot run src/index.ts
42 |   "license": "MIT"
       ^
warn: Duplicate key "license" in object literal
   at <repo>/node_modules/.bun/[email protected]/node_modules/openelectricity/dist/package.json:42:3

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