Rollback to Helidon 2.3.1 which fixes broken SODA rollback (#369)

Author: ddrechse

grabdish/order-helidon/pom.xml

@@ -23,7 +23,7 @@
     <parent>
         <groupId>io.helidon.applications</groupId>
         <artifactId>helidon-mp</artifactId>
-        <version>2.4.0</version>
+        <version>2.3.1</version>
         <relativePath/>
     </parent>