Bump defu from 6.1.2 to 6.1.6 in /frontend

Bumps [defu](https://github.com/unjs/defu) from 6.1.2 to 6.1.6.
- [Release notes](https://github.com/unjs/defu/releases)
- [Changelog](https://github.com/unjs/defu/blob/main/CHANGELOG.md)
- [Commits](unjs/defu@v6.1.2...v6.1.6)

---
updated-dependencies:
- dependency-name: defu
  dependency-version: 6.1.6
  dependency-type: indirect
...

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

Author: dependabot[bot]

frontend/yarn.lock

@@ -7753,9 +7753,9 @@ define-properties@^1.1.3, define-properties@^1.1.4, define-properties@^1.2.0, de
     object-keys "^1.1.1"
 
 defu@^6.1.2:
-  version "6.1.2"
-  resolved "https://registry.yarnpkg.com/defu/-/defu-6.1.2.tgz#1217cba167410a1765ba93893c6dbac9ed9d9e5c"
-  integrity sha512-+uO4+qr7msjNNWKYPHqN/3+Dx3NFkmIzayk2L1MyZQlvgZb/J1A0fo410dpKrN2SnqFjt8n4JL8fDJE0wIgjFQ==
+  version "6.1.6"
+  resolved "https://registry.yarnpkg.com/defu/-/defu-6.1.6.tgz#20970cc978d9be90ba6c792184a89c92db656e53"
+  integrity sha512-f8mefEW4WIVg4LckePx3mALjQSPQgFlg9U8yaPdlsbdYcHQyj9n2zL2LJEA52smeYxOvmd/nB7TpMtHGMTHcug==
 
 delayed-stream@~1.0.0:
   version "1.0.0"