5.12 regression - namespace-ambigous elements like <a> in blocks are not rendered in SVG namespace

[yagebu]

Describe the bug

The change in #14685 seems to have broken links in blocks within SVGs. Looking at that change, it now infers a "html" namespace (in the else branch) for the <a> as it's not clear from the <a> node itself which namespace it should have.

<svg>
	{#if true}
		<a href="/docs">
			<text x="20" y="40" class="small">{name}</text>
		</a>
	{/if}
</svg>

See playground links below for a reproduction.

A possible temporary workaround is to add a <g> wrapper element

Reproduction

Broken in
https://svelte.dev/playground/c498e7e6bb884b379bf1350e141c85dc
Since
https://svelte.dev/playground/c498e7e6bb884b379bf1350e141c85dc?version=5.12.0
Still worked in
https://svelte.dev/playground/c498e7e6bb884b379bf1350e141c85dc?version=5.11.3

Logs

No response

System Info

n/a, see REPL (Tested in Firefox)

Severity

blocking an upgrade

[dummdidumm]

I fixed a similar bug for snippets, code from that might help fixing this one

[yagebu]

Thanks for the fix :)