build(deps-dev): bump immutable

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](immutable-js/immutable-js@v4.0.0-rc.12...v4.3.8)

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

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

Author: dependabot[bot]

samples/client/petstore/typescript-fetch/builds/sagas-and-records/package-lock.json

@@ -15,7 +15,7 @@
     "build": "tsc && tsc -p tsconfig.esm.json"
   },
   "devDependencies": {
-    "immutable": "^4.0.0-rc.12",
+    "immutable": "^4.3.8",
     "normalizr": "^3.6.1",
     "redux-saga": "^1.1.3",
     "redux-ts-simple": "^3.2.0",