Harmony managed empty placeholder bugfix

[Intron7]

fixes #764

[codecov-commenter]

Codecov Report

❌ Patch coverage is 55.55556% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 88.95%. Comparing base (f8022d7) to head (a2c3db0).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
...pids_singlecell/preprocessing/_harmony/__init__.py	55.55%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #766      +/-   ##
==========================================
- Coverage   88.95%   88.95%   -0.01%     
==========================================
  Files         111      111              
  Lines       10959    10966       +7     
==========================================
+ Hits         9749     9755       +6     
- Misses       1210     1211       +1     

Files with missing lines	Coverage Δ
...pids_singlecell/preprocessing/_harmony/__init__.py	91.63% <55.55%> (-0.14%)	⬇️