poster prop is not declarative (does not update poster when URL changes)

Hello Cloudflare team,

We have a use case where we are using an external 'video picker' list to select a video they want to watch.

Once they click it, we update the props going to the `` component, including the `src` and `poster` props.

The `src` prop seems to take effect, because starting the video does in fact play the selected video, however the poster does not change.

It looks like it's an intended behavior due to the `useMemo` implementation without dependencies here:
https://github.com/cloudflare/stream-react/blob/fda143fde6e235706ae14afc9dc919a11374c15b/src/useIframeSrc.tsx#L53-L59

Which says you can use the SDK to make the changes... but I don't see how.

Thanks in advance - we're hoping to switch to Stream from a competitor but this is blocking our implementation :)

Inizia leggendo src/useIframeSrc.tsx intorno alle righe 53-59, in particolare il comportamento di useMemo descritto nell’issue. Riproduci il caso modificando la prop poster del componente Stream insieme a src, quindi verifica che il poster visualizzato si aggiorni quando cambia l’URL.

Scritto dal modello di indicizzazione a partire dal testo della issue.