The older one was the original and whoever created it did most of the work and should be blessed by the heavens.
The newer one took the older one, and replaced the screenshots of code with markdown equivalents so they could be rendered by Anki while saving memory. You can see this in the difference in the number of images between the two decks. This is the one I'd download and use.
To find a shared deck, I usually go here: https://ankiweb.net/shared/decks
Search for "rust".
You'll find two decks with 550-560 cards.
The older one was the original and whoever created it did most of the work and should be blessed by the heavens.
The newer one took the older one, and replaced the screenshots of code with markdown equivalents so they could be rendered by Anki while saving memory. You can see this in the difference in the number of images between the two decks. This is the one I'd download and use.