Remove stray println from LSPS2 tests

[tnull]

.. which was accidentally introduced in #4040.

[ldk-reviews-bot]

👋 Thanks for assigning @TheBlueMatt as a reviewer!
I'll wait for their review and will help manage the review process.
Once they submit their review, I'll check if a second reviewer would be helpful.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 88.74%. Comparing base (86c6960) to head (907f9f6).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #4041   +/-   ##
=======================================
  Coverage   88.73%   88.74%           
=======================================
  Files         176      176           
  Lines      129106   129105    -1     
  Branches   129106   129105    -1     
=======================================
+ Hits       114567   114568    +1     
- Misses      11937    11940    +3     
+ Partials     2602     2597    -5     

Flag	Coverage Δ
fuzzing	22.31% <ø> (ø)
tests	88.57% <ø> (+<0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[ldk-reviews-bot]

👋 The first review has been submitted!

Do you think this PR is ready for a second reviewer? If so, click here to assign a second reviewer.