chore: minor null assertion removal on search hook

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: utkuakyuz

src/components/DiffViewer/hooks/useSearch.ts

@@ -60,7 +60,7 @@ export function useSearch(
 
  const listContainer = listContainerRef?.current;
  if (listContainer) {
- const handleScroll = () => setTimeout(() => highlightMatches(searchState.term, viewerRef.current!), 100);
+ const handleScroll = () => setTimeout(() => viewerRef.current && highlightMatches(searchState.term, viewerRef.current), 100);
  listContainer.addEventListener("scroll", handleScroll);
  return () => {
  observer.disconnect();