Fix HANA validation query

This commit updates the validation query for HANA. It should use the
fully qualified dummy table name (SYS.DUMMY) to avoid unexpected results
if there is a local table named DUMMY.

Closes gh-15124

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/jdbc/DatabaseDriver.java

@@ -104,7 +104,7 @@ public enum DatabaseDriver {
 	 * @since 2.1.0
 	 */
 	HANA("HDB", "com.sap.db.jdbc.Driver", "com.sap.db.jdbcext.XADataSourceSAP",
-			"SELECT 1 FROM DUMMY") {
+			"SELECT 1 FROM SYS.DUMMY") {
 		@Override
 		protected Collection<String> getUrlPrefixes() {
 			return Collections.singleton("sap");