fix(SelectMenu): filteredOptions might be undefined

[angsanley]

🔗 Linked issue

Resolves #1540

❓ Type of change

• 📖 Documentation (updates to the documentation or readme)
• 🐞 Bug fix (a non-breaking change that fixes an issue)
• 👌 Enhancement (improving an existing functionality)
• ✨ New feature (a non-breaking change that adds functionality)
• 🧹 Chore (updates to the build process or auxiliary tools and libraries)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

In the SelectMenu.vue file, there's this snippet where it checks for filteredOptions.length

<p v-else-if="searchable && query && !filteredOptions.length" :class="uiMenu.option.empty">
  <slot name="option-empty" :query="query">
    No results for "{{ query }}".
  </slot>
</p>
<p v-else-if="!filteredOptions.length" :class="uiMenu.empty">
  <slot name="empty" :query="query">
    No options.
  </slot>
</p>

But because filteredOptions is a computedAsync, there's a possibility that the object itself is still undefined, thus checking for .length will not be possible.

SelectMenu.vue:652 Uncaught (in promise) TypeError: Cannot read properties of undefined (reading 'length')
    at SelectMenu.vue:652:52
    at Proxy.renderFnWithContext (vue.js?v=74953c0b:2286:13)
    at y (render.js?v=5a63436d:1:810)
    at A (render.js?v=5a63436d:1:517)
    at Proxy.<anonymous> (combobox.js?v=5a63436d:1:18470)
    at renderComponentRoot (vue.js?v=74953c0b:2345:17)
    at ReactiveEffect.componentUpdateFn [as fn] (vue.js?v=74953c0b:7457:46)
    at ReactiveEffect.run (vue.js?v=74953c0b:432:19)
    at instance.update (vue.js?v=74953c0b:7588:17)
    at setupRenderEffect (vue.js?v=74953c0b:7598:5)

To solve this issue we can check whether filteredOptions is undefined or not by using optional chaining.

📝 Checklist

• I have linked an issue or discussion.
• I have updated the documentation accordingly.