Use ENKF_TRUNCTION in snake_oil test example

[andreas-el]

🛠️

• PR title captures the intent of the changes, and is fitting for release notes.
• Added appropriate release note label
• Commit history is consistent and clean, in line with the contribution guidelines.
• Make sure unit tests pass locally after every commit (git rebase -i main --exec 'just rapid-tests')

When applicable

• When there are user facing changes: Updated documentation
• New behavior or changes to existing untested code: Ensured that unit tests are added (See Ground Rules).
• Large PR: Prepare changes in small commits for more convenient review
• Bug fix: Add regression test for the bug
• Bug fix: Add backport label to latest release (format: 'backport release-branch-name')

[andreas-el]

Need to address some tests too apparently.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.92%. Comparing base (1c81248) to head (89a0e11).
⚠️ Report is 6 commits behind head on main.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #13493      +/-   ##
==========================================
- Coverage   90.00%   89.92%   -0.09%     
==========================================
  Files         460      460              
  Lines       32332    32372      +40     
==========================================
+ Hits        29101    29111      +10     
- Misses       3231     3261      +30     

Flag	Coverage Δ
cli-tests	37.17% <ø> (-0.06%)	⬇️
fuzz	44.05% <ø> (-0.02%)	⬇️
gui-tests	66.82% <ø> (-0.10%)	⬇️
performance-and-unit-tests	78.03% <ø> (-0.07%)	⬇️
test	45.61% <ø> (-0.02%)	⬇️

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