Found it, please delete the post.
It’s still a valid question even if you found the answer. Not putting the answer below the question means everybody else that comes here with the same question would need to find the answer on their own.
All releases of Tiled are available on GitHub at https://github.com/bjorn/tiled/releases.
Besides that, I believe the itch.io app also has the option to download previous releases, but I don’t know how far back that goes.
Btw, I forgot to ask, why did you want to download Tiled 1.1?