readme: remove demo references (#3393)

README.md

@@ -74,15 +74,6 @@ If you're already familiar with Kubernetes, it's easy to get started with Conste
 
 Learn more: ["Getting started with Constellation" videos series](https://www.youtube.com/playlist?list=PLEhAl3D5WVvRYxO_yI7KzmtJ7rJUyQgNu).
 
-## Live demos
-
-We're running public instances of popular software on Constellation:
-
-* Rocket.Chat: <https://rocket.edgeless.systems/> ([blog post](https://www.edgeless.systems/resource-library/rocket-chat))
-* GitLab: <https://gitlab.edgeless.systems/> ([blog post](https://www.edgeless.systems/resource-library/confidential-gitlab/))
-
-These instances run on CVMs in Azure and Constellation keeps them end-to-end confidential.
-
 ## Documentation
 
 To learn more, see the [documentation](https://docs.edgeless.systems/constellation).