Add React 19 support

[Alexandre-GL]

Big thanks for the work on this very useful library!
Could you please update the peer dependencies to allow React 19 now that it's stable?

[PurrBiscuit]

You can add the following overrides block to your package.json to be able to use this package with React 19 for now:

{
  "name": "example",
  "version": "0.1.0",
  "overrides": {
    "next-navigation-guard": {
      "react": "19.0.0"
    },
  }
}