Fixing bug on PTDF calculation with distributed slack

[alefcastelli]

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[github-actions]

Performance Results

Version	Precompile Time
Main	3.307908356
This Branch	3.167877621

Version	Execute Time
Main-Build PTDF First	7.713823033
Main-Build PTDF Second	0.225342885
Main-Build Ybus First	0.478345355
Main-Build Ybus Second	0.011046494
Main-Build LODF First	0.681073316
Main-Build LODF Second	0.351613654
This Branch-Build PTDF First	7.868789957
This Branch-Build PTDF Second	0.231680325
This Branch-Build Ybus First	0.498887552
This Branch-Build Ybus Second	0.010603107
This Branch-Build LODF First	0.691923537
This Branch-Build LODF Second	0.36438412

[jd-lara]

@alefcastelli the code looks ok to me but there is a mistake in the test that uses the wrong keyword argument

[codecov]

Codecov Report

Merging #47 (c4dde3f) into main (82c5591) will increase coverage by 1.74%.
The diff coverage is 78.57%.

❗ Current head c4dde3f differs from pull request most recent head 4841224. Consider uploading reports for the commit 4841224 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #47      +/-   ##
==========================================
+ Coverage   70.27%   72.02%   +1.74%     
==========================================
  Files          14       14              
  Lines        1006     1008       +2     
==========================================
+ Hits          707      726      +19     
+ Misses        299      282      -17     

Flag	Coverage Δ
unittests	72.02% <78.57%> (+1.74%)	⬆️

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

Files Changed	Coverage Δ
src/ptdf_calculations.jl	86.25% <78.57%> (+11.09%)	⬆️

... and 1 file with indirect coverage changes