Custom font provider only preloads first weight when font family has multiple weights

[mateusmcordeiro]

## Description

When using a custom font provider with multiple font files for different weights of the same font family, only the first weight is preloaded. The subsequent weights are ignored even though `preload: true` is set.

### Environment

- `@nuxt/fonts` version: "^0.13.0"
- Nuxt version: "^4.2.1"

### Configuration

**`nuxt.config.ts`**
```typescript
fonts: {
  providers: {
    custom: '@/providers/fontProvider.ts'
  },
  families: [
    { name: 'Inter', provider: 'custom', preload: true },
    { name: 'Matter SQ', provider: 'custom', preload: true },
    { name: 'Matter', provider: 'custom', preload: false }
  ],
  experimental: {
    processCSSVariables: true
  }
}

fontProvider.ts

'Matter SQ': [
  {
    src: [{ url: '/fonts/matter-sq/MatterSQ-Light.woff2', format: 'woff2' }],
    weight: 300,
    style: 'normal',
    display: 'swap'
  },
  {
    src: [{ url: '/fonts/matter-sq/MatterSQ-Regular.woff2', format: 'woff2' }],
    weight: 400,
    style: 'normal',
    display: 'swap'
  }
]

Current behavior

Only the first font weight (300) is preloaded:

<link rel="preload" as="font" crossorigin="" href="/fonts/Inter-4.1/web/InterVariable-subset.woff2">
<link rel="preload" as="font" crossorigin="" href="/fonts/matter-sq/MatterSQ-Light.woff2">

Expected behavior

All font weights returned by the provider should be preloaded:

<link rel="preload" as="font" crossorigin="" href="/fonts/Inter-4.1/web/InterVariable-subset.woff2">
<link rel="preload" as="font" crossorigin="" href="/fonts/matter-sq/MatterSQ-Light.woff2">
<link rel="preload" as="font" crossorigin="" href="/fonts/matter-sq/MatterSQ-Regular.woff2">

Additional context

• The @font-face rules are generated correctly for all weights
• Only the preload behavior is affected
• I also tried using the weights option (weights: [300, 400]) but it didn't change the behavior

Workaround

Currently using manual preload links in app.head.link as a workaround:

app: {
  head: {
    link: [
      {
        rel: 'preload',
        href: '/fonts/matter-sq/MatterSQ-Light.woff2',
        as: 'font',
        type: 'font/woff2',
        crossorigin: 'anonymous'
      },
      {
        rel: 'preload',
        href: '/fonts/matter-sq/MatterSQ-Regular.woff2',
        as: 'font',
        type: 'font/woff2',
        crossorigin: 'anonymous'
      }
    ]
  }
}

[twnty-dev]

the same problem.

@danielroe maybe we do smth wrong?