build(deps): bump defu from 6.1.4 to 6.1.6 in /docs

Bumps [defu](https://github.com/unjs/defu) from 6.1.4 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@v6.1.4...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]

docs/yarn.lock

@@ -856,9 +856,9 @@ csstype@^3.2.3:
   integrity sha512-z1HGKcYy2xA8AGQfwrn0PAy+PB7X/GSj3UVJW9qKyn43xWa+gl5nXmU4qqLMRzWVLFC8KusUX8T/0kCiOYpAIQ==
 
 defu@^6.1.4:
-  version "6.1.4"
-  resolved "https://registry.yarnpkg.com/defu/-/defu-6.1.4.tgz#4e0c9cf9ff68fe5f3d7f2765cc1a012dfdcb0479"
-  integrity sha512-mEQCMmwJu317oSz8CwdIOdwf3xMif1ttiM8LTufzc3g6kR+9Pe236twL8j3IYT1F7GfRgGcW6MWxzZjLIkuHIg==
+  version "6.1.6"
+  resolved "https://registry.yarnpkg.com/defu/-/defu-6.1.6.tgz#20970cc978d9be90ba6c792184a89c92db656e53"
+  integrity sha512-f8mefEW4WIVg4LckePx3mALjQSPQgFlg9U8yaPdlsbdYcHQyj9n2zL2LJEA52smeYxOvmd/nB7TpMtHGMTHcug==
 
 dequal@^2.0.0:
   version "2.0.3"