dep(deps): bump the next-js group with 2 updates

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


Updates `next` from 15.3.4 to 15.4.5
- [Release notes](https://github.com/vercel/next.js/releases)
- [Changelog](https://github.com/vercel/next.js/blob/canary/release.js)
- [Commits](vercel/next.js@v15.3.4...v15.4.5)

Updates `next-rspack` from 15.3.4 to 15.4.5
- [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/v15.4.5/packages/next-rspack)

---
updated-dependencies:
- dependency-name: next
  dependency-version: 15.4.5
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: next-js
- dependency-name: next-rspack
  dependency-version: 15.4.5
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: next-js
...

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Author: dependabot[bot]