Bump immutable from 5.1.5 to 5.1.9 in /docs

Bumps [immutable](https://github.com/immutable-js/immutable-js) from 5.1.5 to 5.1.9.
- [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/v5.1.5...v5.1.9)

---
updated-dependencies:
- dependency-name: immutable
  dependency-version: 5.1.9
  dependency-type: indirect
...

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

docs/package-lock.json

@@ -19,6 +19,7 @@
         "docusaurus-plugin-openapi-docs": "^4.5.1",
         "docusaurus-theme-openapi-docs": "^4.5.1",
         "js-yaml": "^4.1.1",
+        "marked": "^16.4.2",
         "prism-react-renderer": "^2.4.1",
         "raw-loader": "^4.0.2",
         "react": "^18.3.1",
@@ -12320,9 +12321,9 @@
       }
     },
     "node_modules/immutable": {
-      "version": "5.1.5",
-      "resolved": "https://registry.npmjs.org/immutable/-/immutable-5.1.5.tgz",
-      "integrity": "sha512-t7xcm2siw+hlUM68I+UEOK+z84RzmN59as9DZ7P1l0994DKUWV7UXBMQZVxaoMSRQ+PBZbHCOoBt7a2wxOMt+A==",
+      "version": "5.1.9",
+      "resolved": "https://registry.npmjs.org/immutable/-/immutable-5.1.9.tgz",
+      "integrity": "sha512-m8nVez3rwrgmWxtLMt1ZYXB2Lv7OKYn/disyxAlSDYAlKSlFoPPfIAmAM/M5xqL4m4C/wAPw7S2/CNaUii1Hxg==",
       "license": "MIT"
     },
     "node_modules/import-fresh": {