Fix Javadoc since tag for class ExpressionAuthorizationDecision

Closes gh-12411

core/src/main/java/org/springframework/security/authorization/ExpressionAuthorizationDecision.java

@@ -22,7 +22,7 @@ import org.springframework.expression.Expression;
  * Represents an {@link AuthorizationDecision} based on a {@link Expression}
  *
  * @author Marcus Da Coregio
- * @since 5.6
+ * @since 5.8
  */
 public class ExpressionAuthorizationDecision extends AuthorizationDecision {