fix: replace var with Object in old code for sequenced-collections (Java 8 compat)

Agent-Logs-Url: https://github.com/javaevolved/javaevolved.github.io/sessions/8cfb63c8-1db5-417c-879c-d67adf70e8b5

Co-authored-by: brunoborges <129743+brunoborges@users.noreply.github.com>

Author: Copilot

content/collections/sequenced-collections.yaml

@@ -11,9 +11,9 @@ oldApproach: "Index Arithmetic"
 modernApproach: "getFirst/getLast"
 oldCode: |-
   // Get last element
-  var last = list.get(list.size() - 1);
+  Object last = list.get(list.size() - 1);
   // Get first
-  var first = list.get(0);
+  Object first = list.get(0);
   // Reverse iteration: manual
 modernCode: |-
   var last = list.getLast();