chore: deactivate batch after async derived resolves (#17865)

Extracted from #17805. Similar to #17864, I'm not aware of any bugs
resulting from this, but the fact that we're setting `current_batch`
before calling `internal_set` and then not _unsetting_ `current_batch`
feels like something that could potentially bite us.

packages/svelte/src/internal/client/reactivity/deriveds.js

@@ -196,6 +196,8 @@ export function async_derived(fn, label, location) {
 			if (decrement_pending) {
 				decrement_pending();
 			}
+
+			batch.deactivate();
 		};
 
 		d.promise.then(handler, (e) => handler(null, e || 'unknown'));