Add Nuxt 4 compatibility

[luc122c]

Closes #63 by adding ^4.0.0 to the compatibility range for Nuxt.

I have not yet tested this, although I have been using this module with compatibilityVersion: 4 for some time without issue.

[Barbapapazes]

It should works without this but let's wait for the official Nuxt Module migration guide to know.

[luc122c]

There is a similar issue with the semver check here: vuejs/pinia#3009 (comment)

[ceigey]

I had to:

• manually remove the module from nuxt.config.ts
• run npm remove nuxt-authorization
• re-run npx nuxi module add nuxt-authorization

... to get that message to go away (but maybe I was just overthinking things and npx nuxi module add nuxt-authorization@latest would work).

This is with the latest update from @Barbapapazes which introduced the simpler >=3.0.0 semver check (e.g. not this PR), and Nuxt 4 stable (e.g. just 4.0.0 not 4.0.0-alpha).