You do not need to disinfect the tank unless the fish was died of some kind of contagious disease or parasites. It unlikely the cause unless you have brought in a source for disease or parasites lately.
The fish itself was also dead for only a short amount of time. There wouldn't be any bacteria. You can just clean it with tap water before you put it away.
If your reason for not getting a fish any time soon is all because the concern for harmful bacteria, you might as well get a new fish right away before nitrogen cycle crush. In that case, you shouldn't even wash the tank with untreated tap water because chlorine will kill the good bacteria in the filter which keeps the nitrogen cycle going. If you have changed your mind on getting new fish, might as well just do two to three partial water change in a row before head out to get a new fish.
