docs: replace legacy line‑dot‑left‑horizontal icons with unified dot icon across docs

apps/docs/content/(01-linear-structures)/stack/150-evaluate-reverse-polish-notation.mdx

@@ -1,7 +1,7 @@
 ---
 title: '150. Evaluate Reverse Polish Notation'
 description: You are given an array of strings tokens that represents an arithmetic expression in a Reverse Polish Notation
-icon: line-dot-left-horizontal
+icon: dot
 sidebar:
   label: 'Evaluate Reverse Polish Notation'
   badge: 'Medium'