chore: update conventional-changelog-conventionalcommits to latest version 9.1.0

Updates from version 8.0.0 to 9.1.0 to ensure compatibility with the latest
conventional commits specification and improvements.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: nkmr-jp

package-lock.json

@@ -39,7 +39,7 @@
     "@semantic-release/changelog": "^6.0.3",
     "@semantic-release/git": "^10.0.1",
     "@semantic-release/github": "^11.0.3",
-    "conventional-changelog-conventionalcommits": "^8.0.0",
+    "conventional-changelog-conventionalcommits": "^9.1.0",
     "@types/jest": "^29.5.14",
     "@types/js-yaml": "^4.0.9",
     "@types/node": "20.17.57",