Changelog entry

Author: BPScott

UNRELEASED.md

@@ -23,6 +23,7 @@ Use [the changelog guidelines](https://git.io/polaris-changelog-guidelines) to f
 ### Development workflow
 
 - Updated our CI accessibility checks to use the axe runnner provided by Storybook's a11y addon. Now now errors match between CI and local runs in Storybook ([#3284](https://github.com/Shopify/polaris-react/pull/3284))
+- Updated sewing-kit to 0.140.0 and TypeScript to 4.0.0 ([#3566](https://github.com/Shopify/polaris-react/pull/3566))
 
 ### Dependency upgrades