docs: remove demo.keboola.com links from data apps documentation

Removes references to demo.keboola.com configurations that are being
decommissioned. Keeps live app links and source code references intact.

Ref: AJDA-2550
Co-Authored-By: Vaclav Nosek <weenca@gmail.com>

Author: devin-ai-integration[bot]

data-apps/index.md

@@ -213,14 +213,12 @@ For example, there may be a conflict with the specified packages:
 
 Simple demonstration of Streamlit code deployment.
 
-- [Configuration](https://demo.keboola.com/app/data-apps/75298630)
 - [Live App](https://hello-world-75299519.hub.north-europe.azure.keboola.com)
 
 ### Titanic Demo App
 
 Interactive data exploration with visualizations and filters.
 
-- [Configuration](https://demo.keboola.com/app/data-apps/49752130)
 - [Source Code](https://github.com/keboola/titanic-data-app)
 - [Live App](https://titanic-demo-app-deployed-from-a-github-repository-49752295.hub.north-europe.azure.keboola.com/)
 

data-apps/streamlit/index.md

@@ -55,7 +55,7 @@ There are two ways to deploy a Streamlit data app:
 
 ### Code
 
-For simple use cases where your Streamlit code fits on one page, paste the code directly into a text area. This deployment type is ideal for simple apps or for testing. Check out our [Titanic Demo App](https://demo.keboola.com/app/data-apps/49752130) or [this example from Streamlit docs](https://docs.streamlit.io/library/get-started/create-an-app#lets-put-it-all-together).
+For simple use cases where your Streamlit code fits on one page, paste the code directly into a text area. This deployment type is ideal for simple apps or for testing. Check out [this example from Streamlit docs](https://docs.streamlit.io/library/get-started/create-an-app#lets-put-it-all-together).
 
 {: .image-popup}
 ![Code deployment](/data-apps/streamlit/development-type-code.png)