fix(deps): update dependency postcss-preset-mantine to ^1.15.0 (#387)

Co-authored-by: homarr-renovate[bot] <158783068+homarr-renovate[bot]@users.noreply.github.com>

apps/nextjs/package.json

@@ -49,7 +49,7 @@
     "dotenv": "^16.4.5",
     "jotai": "^2.8.0",
     "next": "^14.2.2",
-    "postcss-preset-mantine": "^1.14.4",
+    "postcss-preset-mantine": "^1.15.0",
     "react": "18.2.0",
     "react-dom": "18.2.0",
     "sass": "^1.75.0",