astro-webmanifest compatability with Astro 3

Currently astro-webmanifest is incompatable with Astro 3 because of dependency from sharp@^0.31.3
On build it gives error:
```js
MissingSharp: Could not find Sharp. Please install Sharp (`sharp`) manually into your project.
```

Updating dependency to sharp@^0.32.5 will fix the problem