Ccomparison between signed and unsigned values, causing a error (#54318)

Summary:
We saw this error while integrating  changes in react native windows
microsoft/react-native-windows#15292
Fixed type consistency in cloneMultipleRecursive by using size_t for loop iterator to properly match vector size type, improving type safety when iterating over children nodes.

## Changelog:
[GENERAL][FIXED] - Use size_t instead of int for vector iteration in cloneMultipleRecursive
<!-- Help reviewers and the release process by writing your own changelog entry.

Pick one each for the category and type tags:

|GENERAL|FIXED|- Message

For more details, see:
https://reactnative.dev/contributing/changelogs-in-pull-requests

Pull Request resolved: #54318

Reviewed By: christophpurrer

Differential Revision: D85800905

Pulled By: javache

fbshipit-source-id: 2fdb539e1c9af56eebdd5c7a900fa0e697bcab3a

Author: Harini Malothu

packages/react-native/ReactCommon/react/renderer/core/ShadowNode.cpp

@@ -421,7 +421,7 @@ std::shared_ptr<ShadowNode> cloneMultipleRecursive(
   std::shared_ptr<std::vector<std::shared_ptr<const ShadowNode>>> newChildren;
   auto count = childrenCount.at(family);
 
-  for (int i = 0; count > 0 && i < children.size(); i++) {
+  for (size_t i = 0; count > 0 && i < children.size(); i++) {
     const auto childFamily = &children[i]->getFamily();
     if (childrenCount.contains(childFamily)) {
       count--;