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

Author: renovate[bot]

package.json

@@ -16,11 +16,11 @@
     "format:check": "prettier --check src/**/*.{js,jsx,ts,tsx,css,md}"
   },
   "dependencies": {
-    "@docusaurus/core": "3.8.1",
-    "@docusaurus/plugin-ideal-image": "3.8.1",
-    "@docusaurus/preset-classic": "3.8.1",
-    "@docusaurus/theme-mermaid": "3.8.1",
-    "@docusaurus/theme-search-algolia": "3.8.1",
+    "@docusaurus/core": "3.9.1",
+    "@docusaurus/plugin-ideal-image": "3.9.1",
+    "@docusaurus/preset-classic": "3.9.1",
+    "@docusaurus/theme-mermaid": "3.9.1",
+    "@docusaurus/theme-search-algolia": "3.9.1",
     "@mdx-js/react": "3.1.1",
     "clsx": "2.1.1",
     "eslint": "^9.29.0",