There's really no reason to do this because it's essentially a declaration of war against Russia. If you're willing to go to war with Russia, just send the Coast Guard to seize vessels.
https://www.reuters.com/world/italy-seizes-yacht-owned-by-ru...
Sequestering all generic ships sailing under Russian flag would be a different, and much more serious, action.
Now, Russia might declare ware and cite this as a reason, but it’s not. It’s more like state sponsored terrorism. Like how Iran isn’t actually declaring war on Israel with its Hezbollah sponsorship.
Similarly, the US wasn’t declaring war on the USSR when it armed Afghan rebels in the 80s.
However it would put at risk merchant fleets all over the world through reprisal, and I think the rest of the world has a lot more to lose in this game than Russia. For this reason, I do not think this will be ratified.