Bump flatted from 3.4.1 to 3.4.2 in /Extension (#14304)

Bumps [flatted](https://github.com/WebReflection/flatted) from 3.4.1 to 3.4.2.
- [Commits](WebReflection/flatted@v3.4.1...v3.4.2)

---
updated-dependencies:
- dependency-name: flatted
  dependency-version: 3.4.2
  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]

Extension/yarn.lock

@@ -3037,9 +3037,9 @@ flat@^5.0.2:
   integrity sha1-jKb+MyBp/6nTJMMnGYxZglnOskE=
 
 flatted@^3.2.9, flatted@^3.4.1:
-  version "3.4.1"
-  resolved "https://pkgs.dev.azure.com/azure-public/VisualCpp/_packaging/cpp_PublicPackages/npm/registry/flatted/-/flatted-3.4.1.tgz#84ccd9579e76e9cc0d246c11d8be0beb019143e6"
-  integrity sha1-hMzZV5526cwNJGwR2L4L6wGRQ+Y=
+  version "3.4.2"
+  resolved "https://pkgs.dev.azure.com/azure-public/VisualCpp/_packaging/cpp_PublicPackages/npm/registry/flatted/-/flatted-3.4.2.tgz#f5c23c107f0f37de8dbdf24f13722b3b98d52726"
+  integrity sha1-9cI8EH8PN96NvfJPE3IrO5jVJyY=
 
 flush-write-stream@^1.0.2:
   version "1.1.1"