Bump the next group with 2 updates

Bumps the next group with 2 updates: [next](https://github.com/vercel/next.js) and [eslint-config-next](https://github.com/vercel/next.js/tree/HEAD/packages/eslint-config-next).


Updates `next` from 15.5.4 to 15.5.5
- [Release notes](https://github.com/vercel/next.js/releases)
- [Changelog](https://github.com/vercel/next.js/blob/canary/release.js)
- [Commits](vercel/next.js@v15.5.4...v15.5.5)

Updates `eslint-config-next` from 15.5.4 to 15.5.5
- [Release notes](https://github.com/vercel/next.js/releases)
- [Changelog](https://github.com/vercel/next.js/blob/canary/release.js)
- [Commits](https://github.com/vercel/next.js/commits/v15.5.5/packages/eslint-config-next)

---
updated-dependencies:
- dependency-name: next
  dependency-version: 15.5.5
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: next
- dependency-name: eslint-config-next
  dependency-version: 15.5.5
  dependency-type: direct:development
  update-type: version-update:semver-patch
  dependency-group: next
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

package-lock.json

@@ -56,7 +56,7 @@
     "@types/react-dom": "^19.2.2",
     "esbuild": "0.25.10",
     "eslint": "^9.37.0",
-    "eslint-config-next": "15.5.4",
+    "eslint-config-next": "15.5.5",
     "eslint-config-prettier": "^10.1.8",
     "jest": "^30.2.0",
     "jest-environment-jsdom": "^30.2.0",
@@ -77,7 +77,7 @@
     "isomorphic-dompurify": "^2.28.0",
     "jsonwebtoken": "^9.0.2",
     "jwt-decode": "^4.0.0",
-    "next": "15.5.4",
+    "next": "15.5.5",
     "next-auth": "^5.0.0-beta.29",
     "nhsuk-react-components": "^5.0.0",
     "openid-client": "^6.8.1",