fix: Add back missing split fields

[ksbrar]

As far as I can tell this line was too extensive for split configs, and it was responsible for the column fields being removed. I changed the function so that it only redacts type.

This is what the keys looked like before and after the original call to remove_duplicate_fields:

odict_keys(['type', 'column', 'probabilities'])
odict_keys(['probabilities'])

[github-actions]

Unit Test Results

         6 files  ±0           6 suites  ±0   3h 27m 25s ⏱️ - 26m 22s
  3 532 tests ±0    3 461 ✔️ ±0    71 💤 ±0  0 ❌ ±0 
10 596 runs  ±0  10 368 ✔️ ±0  228 💤 ±0  0 ❌ ±0 

Results for commit e063a4b. ± Comparison against base commit 5bcdf79.