build(deps): bump @primer/octicons-react from 19.38.0 to 19.40.0 in /ui

Bumps [@primer/octicons-react](https://github.com/primer/octicons) from 19.38.0 to 19.40.0.
- [Release notes](https://github.com/primer/octicons/releases)
- [Changelog](https://github.com/primer/octicons/blob/main/CHANGELOG.md)
- [Commits](https://github.com/primer/octicons/compare/@primer/octicons-react@19.38.0...@primer/octicons-react@19.40.0)

---
updated-dependencies:
- dependency-name: "@primer/octicons-react"
  dependency-version: 19.40.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

ui/package-lock.json

@@ -18,7 +18,7 @@
     "@github/markdown-toolbar-element": "^2.2.3",
     "@modelcontextprotocol/client": "^2.3.1",
     "@modelcontextprotocol/ext-apps": "^2.0.3",
-    "@primer/octicons-react": "^19.38.0",
+    "@primer/octicons-react": "^19.40.0",
     "@primer/primitives": "^11.10.0",
     "@primer/react": "^38.40.1",
     "react": "^19.3.0",