Add support for Svelte 5 @render syntax

[Robertsson]

Changes

• Adds support for Svelte 5's new @render syntax in Astro integration
• Maintains backward compatibility with traditional Svelte slots
• Updates both client and server integrations to handle both patterns:
  • Legacy: $$slots and <slot />
  • New: @render children and {@render children()}

<!-- Legacy pattern  -->
  <slot />

<!-- New Svelte 5 pattern  -->
{@render children()}

Can't be combined in the same component.

Svelte 5 Render »

Testing

Created test Astro project with Svelte integration
Tested with both legacy and new syntax patterns

Docs

No documentation probably needed for this. Example project for svelte might need to be updated later on.

[changeset-bot]

🦋 Changeset detected

Latest commit: 694e33a

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[bluwy]

Thanks for fixing this! I tested it locally and it seems to work well too. Let's merge this one before working on full Svelte 5 support at #12364

[bluwy]

I just realized this is merged into next, should be main...