feat: update colors for v4 (#10660)

Porting changes from https://github.com/chatwoot/chatwoot/pull/10552

---------

Co-authored-by: Pranav <pranav@chatwoot.com>
Co-authored-by: Sivin Varghese <64252451+iamsivin@users.noreply.github.com>
Co-authored-by: Vishnu Narayanan <vishnu@chatwoot.com>
Co-authored-by: Sojan <sojan@pepalo.com>
Co-authored-by: iamsivin <iamsivin@gmail.com>
Co-authored-by: Pranav <pranavrajs@gmail.com>

app/javascript/dashboard/modules/conversations/components/MessageContextMenu.vue

@@ -274,7 +274,7 @@ export default {
   }
 
   hr {
-    @apply m-1 border-b border-solid border-slate-50 dark:border-slate-800/50;
+    @apply m-1 border-b border-solid border-n-strong;
   }
 }