Refactor nil check logic per code review feedback

Simplified the listIndentsChild computation by moving it inside the nil check,
avoiding redundant nil check and limiting listLine scope.

Co-authored-by: jakebailey <[email protected]>

Author: Copilot

internal/format/indent.go

@@ -66,11 +66,11 @@ func getIndentationForNodeWorker(
 			// }, {                  itself contributes nothing.
 			//   prop: 1        L3 - The indentation of the second object literal is best understood by
 			// })                    looking at the relationship between the list and *first* list item.
-			var listLine int
+			var listIndentsChild bool
 			if firstListChild != nil {
-				listLine, _ = getStartLineAndCharacterForNode(firstListChild, sourceFile)
+				listLine, _ := getStartLineAndCharacterForNode(firstListChild, sourceFile)
+				listIndentsChild = listLine > containingListOrParentStartLine
 			}
-			listIndentsChild := firstListChild != nil && listLine > containingListOrParentStartLine
 			actualIndentation := getActualIndentationForListItem(current, sourceFile, options, listIndentsChild)
 			if actualIndentation != -1 {
 				return actualIndentation + indentationDelta