Head propagation graph walking on new pages

[matthewp]

Changes

• We walk the graph when we encounter a module that has head content, such as transition: directives, walking up parents to mark them with metadata in-tree.
• If you load a page that contains a module with head content, and then later load another page (as happens in dev), we need to check dependencies so that we can mark the new page with the in-tree if needed.
• Fixes Nesting Astro components prevents transition directives from animating #8392

Testing

• New fixture test added mimicking Nesting Astro components prevents transition directives from animating #8392

Docs

N/A, bug fix

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[bluwy]

If we're handling the propagation in resolveId. Could we remove the similar code in the transform hook entirely? Or do they work differently?

[matthewp]

I was thinking about this... I think we probably could. I don't fully trust the test coverage though. I'd rather leave a TODO and try and remove it later when feeling more brave.

[bluwy]

Works for me 👍 Probably worth circle back whenever possible as it touches on perf