Test Styles Build Chain, Quick Way

Steps

1. See how many stylesheets are built on main branch:
   1. cd libs/core-styles
   2. git checkout main (or the base branch of a PR)
   3. npm ci
   4. npm run build
   5. find dist -type f | wc -l
2. Clear CSS build output:
   1. rm -rf dist
3. See how many stylesheets are built on the branch to test:
   1. git checkout the/branch-to-test
   2. npm ci
   3. npm run build — ❗️ verify no error occurs
   4. find dist -type f | wc -l
4. Verify same number of files is output as before this PR.