fixes the error/warning CSS classname of instruction attachment (#238917

)

[prompts]: fixes the error/warning CSS classname of instruction attachment

src/vs/workbench/contrib/chat/browser/attachments/instructionsAttachment/instructionsAttachment.ts

@@ -120,7 +120,7 @@ export class InstructionsAttachmentWidget extends Disposable {
 			const isWarning = !isRootError;
 
 			this.domNode.classList.add(
-				(isWarning) ? 'error' : 'warning',
+				(isWarning) ? 'warning' : 'error',
 			);
 
 			const errorCaption = (isWarning)