Bump immutable from 4.0.0-rc.12 to 4.3.8

Bumps [immutable](https://github.com/immutable-js/immutable-js) from 4.0.0-rc.12 to 4.3.8.
- [Release notes](https://github.com/immutable-js/immutable-js/releases)
- [Changelog](https://github.com/immutable-js/immutable-js/blob/main/CHANGELOG.md)
- [Commits](https://github.com/immutable-js/immutable-js/compare/v4.0.0-rc.12...v4.3.8)

---
updated-dependencies:
- dependency-name: immutable
  dependency-version: 4.3.8
  dependency-type: direct:production
...

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

package.json

@@ -55,7 +55,7 @@
     "i18next-resources-to-backend": "1.2.1",
     "iframe-resizer-react": "1.1.0",
     "immer": "9.0.6",
-    "immutable": "4.0.0-rc.12",
+    "immutable": "4.3.8",
     "is-ci": "2.0.0",
     "jquery": "3.7.1",
     "jquery-typeahead": "2.11.1",