fix(deps): update docusaurus monorepo to v3.9.1

Author: ibm-mend-app[bot]

package.json

@@ -14,17 +14,17 @@
     "write-heading-ids": "docusaurus write-heading-ids"
   },
   "dependencies": {
-    "@docusaurus/core": "3.8.1",
-    "@docusaurus/preset-classic": "3.8.1",
+    "@docusaurus/core": "3.9.1",
+    "@docusaurus/preset-classic": "3.9.1",
     "@mdx-js/react": "^3.0.0",
     "clsx": "^2.0.0",
     "prism-react-renderer": "^2.3.0",
     "react": "^19.0.0",
     "react-dom": "^19.0.0"
   },
   "devDependencies": {
-    "@docusaurus/module-type-aliases": "3.8.1",
-    "@docusaurus/types": "3.8.1"
+    "@docusaurus/module-type-aliases": "3.9.1",
+    "@docusaurus/types": "3.9.1"
   },
   "browserslist": {
     "production": [