fix(deps): update nextjs monorepo to v15.3.0 (#2838)

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

apps/nextjs/package.json

@@ -74,7 +74,7 @@
     "glob": "^11.0.1",
     "jotai": "^2.12.2",
     "mantine-react-table": "2.0.0-beta.9",
-    "next": "15.2.5",
+    "next": "15.3.0",
     "postcss-preset-mantine": "^1.17.0",
     "prismjs": "^1.30.0",
     "react": "19.1.0",