demo: use closable prop (#43542)

* Update closable.tsx

Added `closable` prop

Signed-off-by: Albert E. Hidalgo Taveras <35310226+itsalb3rt@users.noreply.github.com>

* Apply suggestions from code review

Signed-off-by: afc163 <afc163@gmail.com>

---------

Signed-off-by: Albert E. Hidalgo Taveras <35310226+itsalb3rt@users.noreply.github.com>
Signed-off-by: afc163 <afc163@gmail.com>
Co-authored-by: afc163 <afc163@gmail.com>

components/alert/demo/closable.tsx

@@ -10,14 +10,14 @@ const App: React.FC = () => (
     <Alert
       message="Warning Text Warning Text Warning TextW arning Text Warning Text Warning TextWarning Text"
       type="warning"
-      closeIcon
+      closable
       onClose={onClose}
     />
     <Alert
       message="Error Text"
       description="Error Description Error Description Error Description Error Description Error Description Error Description"
       type="error"
-      closeIcon
+      closable
       onClose={onClose}
     />
   </Space>