fix ensembles from optimization endpoints

[plakrisenko]

If only the names of free parameters are taken https://github.com/ICB-DCM/pyPESTO/blob/main/pypesto/ensemble/ensemble.py#L663,
then maybe the same should be true for the parameter values

[codecov-commenter]

Codecov Report

Merging #1130 (96f25d1) into develop (160c2a8) will decrease coverage by 3.79%.
Report is 387 commits behind head on develop.
The diff coverage is 87.95%.

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@@             Coverage Diff             @@
##           develop    #1130      +/-   ##
===========================================
- Coverage    88.16%   84.38%   -3.79%     
===========================================
  Files           79      148      +69     
  Lines         5257    11642    +6385     
===========================================
+ Hits          4635     9824    +5189     
- Misses         622     1818    +1196     

Files	Coverage Δ
pypesto/C.py	100.00% <100.00%> (ø)
pypesto/__init__.py	100.00% <100.00%> (ø)
pypesto/engine/__init__.py	100.00% <100.00%> (ø)
pypesto/engine/multi_process.py	100.00% <100.00%> (+7.69%)	⬆️
pypesto/engine/multi_thread.py	100.00% <100.00%> (ø)
pypesto/engine/single_core.py	100.00% <100.00%> (ø)
pypesto/engine/task.py	100.00% <100.00%> (ø)
pypesto/ensemble/__init__.py	100.00% <100.00%> (ø)
pypesto/ensemble/task.py	100.00% <100.00%> (ø)
pypesto/hierarchical/__init__.py	100.00% <100.00%> (ø)
... and 138 more

[vwiela]

Fixes the issue of getting constant predictions.

[dilpath]

Thanks!

[dilpath]

@PaulJonasJost is this an issue in Ensemble.from_optimization_history too?