[Bug]: Synchronize after merge stop pipeline not release oracle db lock

### Apache Hop version?

2.19.0

### Java version?

jdk-21.0.2

### Operating system

Windows

### What happened?

I executed a pipeline, wihch get data from kafka consumer and output to oracle table via Synchronize after merge tranfsfer

when I stop then pileline. there was a oracle lock exist as below

seems the database connection is not properly disconnected, after pipeline stop.

### Issue Priority

Priority: 2

### Issue Component

Component: Hop Gui

Reproduce the issue with a Kafka consumer feeding an Oracle table through Synchronize after merge, then stop the pipeline and inspect whether the database connection is disconnected. Done means stopping the pipeline releases the Oracle lock; add or update a regression test covering this stop behavior if the existing test structure supports it.

Written by the indexing model from the issue text.