Fix banner z-index (#12683)

## Before

![image](https://github.com/user-attachments/assets/177e8ce2-eaba-442c-a10a-e3a44c91114f)

## After
<img width="1338" alt="image"
src="https://github.com/user-attachments/assets/d44da1b7-0d82-4b04-91b4-cbaa404e9da2"
/>

packages/twenty-front/src/modules/information-banner/components/InformationBanner.tsx

@@ -4,6 +4,7 @@ import { Button } from 'twenty-ui/input';
 
 const StyledBanner = styled(Banner)`
   position: absolute;
+  z-index: 1;
 `;
 
 const StyledText = styled.div`