build(deps): bump @shopify/react-i18n from 5.4.0 to 6.0.3

Bumps [@shopify/react-i18n](https://github.com/Shopify/quilt/tree/HEAD/packages/react-i18n) from 5.4.0 to 6.0.3.
- [Release notes](https://github.com/Shopify/quilt/releases)
- [Changelog](https://github.com/Shopify/quilt/blob/main/packages/react-i18n/CHANGELOG.md)
- [Commits](https://github.com/Shopify/quilt/commits/@shopify/react-i18n@6.0.3/packages/react-i18n)

---
updated-dependencies:
- dependency-name: "@shopify/react-i18n"
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

package.json

@@ -13,7 +13,7 @@
         "@pybricks/firmware": "4.13.0-alpha.1",
         "@pybricks/ide-docs": "1.4.0",
         "@pybricks/mpy-cross-v5": "^2.0.0",
-        "@shopify/react-i18n": "^5.3.0",
+        "@shopify/react-i18n": "^6.0.3",
         "@testing-library/dom": "^8.0.0",
         "@testing-library/jest-dom": "^5.11.9",
         "@testing-library/react": "^11.2.5",