refactor(Checkbox): update Checkbox to use CSS Modules behind flag (#4962)

* docs(storybook): enable fast refresh with react plugin

* refactor(Checkbox): update Checkbox to use CSS Modules behind flag

* test(e2e): update Checkbox test with feature flags

* chore: add changeset

* chore: fix eslint errors

* test(vrt): update snapshots

* chore: fix stylelint errors

* chore: update stylelint to error on warnings

* chore: remove unused disables

---------

Co-authored-by: Josh Black <joshblack@users.noreply.github.com>

Author: joshblack

.changeset/light-chefs-bow.md

@@ -0,0 +1,5 @@
+---
+'@primer/react': minor
+---
+
+Update Checkbox component to use CSS Modules behind feature flag