Avoid ArrayIndexOutOfBoundsException in SpEL's Indexer

When index == arrayLength, the array index is also out of bounds.

For this scenario, a SpelEvaluationException should be thrown instead
of ArrayIndexOutOfBoundsException.

Closes gh-23658

spring-expression/src/main/java/org/springframework/expression/spel/ast/Indexer.java

@@ -439,7 +439,7 @@ public class Indexer extends SpelNodeImpl {
 	}
 
 	private void checkAccess(int arrayLength, int index) throws SpelEvaluationException {
-		if (index > arrayLength) {
+		if (index >= arrayLength) {
 			throw new SpelEvaluationException(getStartPosition(), SpelMessage.ARRAY_INDEX_OUT_OF_BOUNDS,
 					arrayLength, index);
 		}