Bump immutable from 5.1.2 to 5.1.5 in /website

Bumps [immutable](https://github.com/immutable-js/immutable-js) from 5.1.2 to 5.1.5.
- [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@v5.1.2...v5.1.5)

---
updated-dependencies:
- dependency-name: immutable
  dependency-version: 5.1.5
  dependency-type: indirect
...

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

Author: dependabot[bot]

website/.yarn/install-state.gz

@@ -3544,9 +3544,9 @@ __metadata:
   linkType: hard
 
 "immutable@npm:^5.0.2":
-  version: 5.1.2
-  resolution: "immutable@npm:5.1.2"
-  checksum: 10c0/da5af92d2c70323c1f9a0e418832c9eef441feadaf6a295a4e07764bd2400c85186872e016071d9253549d58d364160d55dca8dcdf59fd4a6a06c6756fe61657
+  version: 5.1.5
+  resolution: "immutable@npm:5.1.5"
+  checksum: 10c0/8017ece1578e3c5939ba3305176aee059def1b8a90c7fa2a347ef583ebbd38cbe77ce1bbd786a5fab57e2da00bbcb0493b92e4332cdc4e1fe5cfb09a4688df31
   languageName: node
   linkType: hard