Bump js-yaml from 4.1.1 to 4.2.0 in /Extension

Bumps [js-yaml](https://github.com/nodeca/js-yaml) from 4.1.1 to 4.2.0.
- [Changelog](https://github.com/nodeca/js-yaml/blob/master/CHANGELOG.md)
- [Commits](https://github.com/nodeca/js-yaml/commits)

---
updated-dependencies:
- dependency-name: js-yaml
  dependency-version: 4.2.0
  dependency-type: indirect
...

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

Author: dependabot[bot]

Extension/yarn.lock

@@ -3996,9 +3996,9 @@ js-tokens@^4.0.0:
   integrity sha1-GSA/tZmR35jjoocFDUZHzerzJJk=
 
 js-yaml@^4.1.0, js-yaml@^4.1.1:
-  version "4.1.1"
-  resolved "https://pkgs.dev.azure.com/azure-public/VisualCpp/_packaging/cpp_PublicPackages/npm/registry/js-yaml/-/js-yaml-4.1.1.tgz#854c292467705b699476e1a2decc0c8a3458806b"
-  integrity sha1-hUwpJGdwW2mUduGi3swMijRYgGs=
+  version "4.2.0"
+  resolved "https://pkgs.dev.azure.com/azure-public/VisualCpp/_packaging/cpp_PublicPackages/npm/registry/js-yaml/-/js-yaml-4.2.0.tgz#2bd9e85682dd91bd469afb809d816043b3d49524"
+  integrity sha1-K9noVoLdkb1GmvuAnYFgQ7PUlSQ=
   dependencies:
     argparse "^2.0.1"