You do not need to uninstall, but if you are sure you will not be using that machine again then you should deactivate the software. This will free up the activation in case you need it. To deactivate it just open one of the applications and choose Help -> Deactivate. That should deactivate the entire suite.
You are allowed to have two activated installations, so even if you were not able to do anything with the failing machine, you could still install on a second machine without any issue. Also, Adobe Support can deactivate software for machines that are no linger accessible (theft or failure)