Remove analyze custom properties

[alex-page]

This script is awesome but no longer needed in polaris-react

• We have https://polaris-coverage.shopifycloud.com which monitors the use of custom properties and hard coded values.
• CSS custom properties either work and apply the styles or do not
• We are not encountering issues with the creation or removal of custom properties
• We have visual regression testing which will catch styles not working as intended
• This feels repetitive however could be turned into something useful in shopify/web
• Maintaining 1000 lines of code and running a test on every PR is unnecessary

[github-actions]

size-limit report

Path	Size
cjs	166.15 KB (0%)
esm	96.71 KB (0%)
esnext	143.11 KB (0%)
css	34.17 KB (0%)