Update dependency next to v15

package.json

@@ -18,7 +18,7 @@
   "dependencies": {
     "clsx": "1.2.1",
     "concurrently": "8.0.1",
-    "next": "13.4.2",
+    "next": "15.1.6",
     "react": "18.2.0",
     "react-dom": "18.2.0",
     "react-markdown": "8.0.7",
@@ -33,12 +33,12 @@
     "@types/react": "18.2.6",
     "@types/react-dom": "18.2.4",
     "autoprefixer": "10.4.14",
-    "eslint": "9.32.0",
+    "eslint": "8.40.0",
     "eslint-config-next": "latest",
     "postcss": "8.4.23",
     "prettier": "2.8.8",
     "prettier-plugin-tailwindcss": "0.2.8",
-    "tailwindcss": "4.1.11",
+    "tailwindcss": "3.3.2",
     "typescript": "5.0.4"
   }
 }