Hi, Robyn!
Thanks for using The Events Calendar!
We don’t currently have a way to manage this. I have the same issue as I use Pantheon for my personal sites as well. I get around it by moving the license around when there’s an upgrade available. I know that’s klunky but it’s workable as updates are not super-frequent. Don’t worry about the out install messages, they don’t affect the functionality of the plugin at all, just the ability to upgrade when there’s a new version available.
All that said, we are working on a new version of our licensing platform that should alleviate this issue. Stay tuned! I’m sure there will be an announcement when it happens as it will change things a bit.
Let me know if you have any other questions, I’m happy to help!
Cheers,
Trisha