Bug: v1.3.1 is reported as incompatible with Nuxt v4

It seems that #263 does not fully fix v4 support. It does work tho. ```bash ❯ npx nuxi@latest module add @nuxtjs/leaflet@^1.3.1 WARN The module @nuxtjs/leaflet is not compatible with Nuxt 4.0.0 (requires ^3.0.0) ❯ Do you want to continue installing incompatible version? ○ Yes / ● No ```