fix(deps): update nextjs monorepo to v15.2.1 (#611)

* fix(deps): update nextjs monorepo to v15.2.1

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Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

package.json

@@ -28,7 +28,7 @@
     "markdown-it": "^14.0.0",
     "medium-zoom": "^1.1.0",
     "mongodb": "^6.0.0",
-    "next": "15.1.7",
+    "next": "15.2.1",
     "next-sitemap": "^4.0.0",
     "next-themes": "0.4.4",
     "react": "19.0.0",
@@ -51,7 +51,7 @@
     "@tailwindcss/postcss": "^4.0.0",
     "@tailwindcss/typography": "0.5.16",
     "eslint": "9.21.0",
-    "eslint-config-next": "15.1.7",
+    "eslint-config-next": "15.2.1",
     "postcss": "8.5.2",
     "prettier": "3.5.2",
     "tailwindcss": "4.0.11",