[Bug]: Transform XML Join remove namespace xmlns

### Apache Hop version?

2.12

### Java version?

21

### Operating system

Windows

### What happened?

Hello guys,

I have a problem with a transform XML Join, it removes namespace if named xmlns.

I am migrating from Hop version 2.8 to 2.12, and found this bug.

In first picture, i'm showing run result in hop 2.8, work perfect!

In second picture, didn't work.

### Issue Priority

Priority: 3

### Issue Component

Component: Transforms

Start by reproducing the XML Join transform behavior described in the issue on Hop 2.12, then compare the same input and output with Hop 2.8. Trace the XML Join transform's namespace handling and confirm that a namespace named xmlns is preserved as it was in 2.8; done means the regression is covered by a test or reproducible verification.

Written by the indexing model from the issue text.