chore: fix sidebar animation (#40248)

https://github.com/user-attachments/assets/5fd56517-779f-4690-aeaf-071a4dfb1287

Fixes #39927

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

- **Style**
- Removed the width transition animation effect from the sidebar,
resulting in immediate width changes without animation.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

app/client/packages/design-system/widgets/src/components/Sidebar/src/styles.module.css

@@ -40,7 +40,6 @@
   height: 100%;
   width: var(--sidebar-width);
   background-color: transparent;
-  transition: width 300ms ease-in-out;
 }
 
 .mainSidebar[data-side="right"] .fakeSidebar {