Update cms-makeswift example (#40560)
This upgrades @makeswift/runtime to the latest version, which adds
support for the Slot control.
## Documentation / Examples
- [x] Make sure the linting passes by running `pnpm lint`
- [x] The examples guidelines are followed from [our contributing
doc](https://github.com/vercel/next.js/blob/canary/contributing.md#adding-examples)
