fix: website/package.json & website/package-lock.json to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-ETA-2936803
- https://snyk.io/vuln/SNYK-JS-ETA-3261240

website/package.json

@@ -14,9 +14,9 @@
     "write-heading-ids": "docusaurus write-heading-ids"
   },
   "dependencies": {
-    "@docusaurus/core": "2.3.0",
+    "@docusaurus/core": "2.3.1",
     "@docusaurus/plugin-google-gtag": "^2.3.0",
-    "@docusaurus/preset-classic": "2.3.0",
+    "@docusaurus/preset-classic": "2.3.1",
     "@loadable/component": "^5.15.3",
     "@mdx-js/react": "^1.6.22",
     "animate.css": "^4.1.1",