Increase preparation log to error.

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 89.74359% with 4 lines in your changes missing coverage. Please review.

Project coverage is 91.43%. Comparing base (31f7d4b) to head (372e9a2). Report is 13 commits behind head on main.

Files	Patch %	Lines
tests/utils.py	62.50%	3 Missing :warning:
src/unitxt/deprecation_utils.py	75.00%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #959 +/- ## ========================================== + Coverage 91.33% 91.43% +0.09% ========================================== Files 110 109 -1 Lines 11704 11733 +29 ========================================== + Hits 10690 10728 +38 + Misses 1014 1005 -9 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.