Bump js-yaml from 3.14.2 to 3.15.0 in /website/www (#39172)

Bumps [js-yaml](https://github.com/nodeca/js-yaml) from 3.14.2 to 3.15.0.
- [Changelog](https://github.com/nodeca/js-yaml/blob/master/CHANGELOG.md)
- [Commits](nodeca/js-yaml@3.14.2...3.15.0)

---
updated-dependencies:
- dependency-name: js-yaml
  dependency-version: 3.15.0
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

website/www/yarn.lock

@@ -442,9 +442,9 @@ isexe@^2.0.0:
   integrity sha1-6PvzdNxVb/iUehDcsFctYz8s+hA=
 
 js-yaml@^3.13.1:
-  version "3.14.2"
-  resolved "https://registry.yarnpkg.com/js-yaml/-/js-yaml-3.14.2.tgz#77485ce1dd7f33c061fd1b16ecea23b55fcb04b0"
-  integrity sha512-PMSmkqxr106Xa156c2M265Z+FTrPl+oxd/rgOQy2tijQeK5TxQ43psO1ZCwhVOSdnn+RzkzlRz/eY4BgJBYVpg==
+  version "3.15.0"
+  resolved "https://registry.yarnpkg.com/js-yaml/-/js-yaml-3.15.0.tgz#586e5214eafe3e893756a41e979b50d89d3e4a67"
+  integrity sha512-ttBQIIQPDeLjpPOohtUdXuXUVoA2uIB6fEH9HyJ7234s5mBJ5wTx20njxplLZQgLaOfpmPQA7X2t5AX6tIPbog==
   dependencies:
     argparse "^1.0.7"
     esprima "^4.0.0"