Inspecting the code inside one offending webpage, I apparently could remove it for good.
In your web browser (in my case Firefox) you need to use some flavour of ADBlocker (in my case I use µBlock origin).
Whatever, go to this favourite adblocker and look for some kind of "add custom filters" options. Once located, add and apply these 2 rules (anyway, the first one should be the only needed, as far as I've investigated):
Once added, reload the offending page and tell us your success.
In my case it seems I've ditched this damned piece of Google code once and for all. OTOH, (and luckily), the official "Google Translate" domained page seems to be still working with all its functionalities, so my filter seems good.
As I said, try it and tell us your success.