Clearly describe the bug

The *-notation rules added in 13.5.0 don't report values assigned to SCSS variables. They work fine when assigned to a CSS property directly.

Which rule, if any, is the bug related to?

• alpha-value-notation
• color-function-notation
• hue-degree-notation

What code is needed to

To reproduce:

$ npm pack [email protected]
npm notice
npm notice 📦  [email protected]
npm notice === Tarball Contents ===
npm notice 6.1kB  dist/.DS_Store
npm notice 599B   dist/_constants.js
npm notice 22.3kB dist/_utils.js
npm notice 8.2kB  dist/babel-external.js
npm notice 46B    babel-test.js
npm notice 753B   dist/babel-test.js
npm notice 41B    babel.js
npm notice 10.4k

Can we have numeric values allowed for tokens like fontWeights, zIndices, linHeights`, etc?
Example: https://codesandbox.io/s/stitches-ts-issue-forked-voh43?file=/src/stitches.config.ts

Recently @devrnt opened up a PR to improve the setup with a theme(#189) and I realised that it'll be awesome to have that section expanded for each case.