update: Default Demo Login Credentials to noah@demo.dev (#7308)

This PR updates the default login credentials for the demo environment.
The current default is set to tim@apple.dev, and we want to change it
to:

Email: `noah@demo.dev`
Password: `Applecar2025`

Changes:

- Updated default demo login email from tim@apple.dev to noah@demo.dev

Resolves #7304

---------

Co-authored-by: Félix Malfait <felix@twenty.com>

README.md

@@ -43,7 +43,7 @@ We felt the need for a CRM platform that empowers rather than constrains. We bel
 Go to <a href="https://demo.twenty.com/">demo.twenty.com</a> and login with the following credentials:
 
 ```
-email: noah@demo.dev
+email: tim@apple.dev
 password: Applecar2025
 ```