♻️ Simplify noise-aware simulation in ECC framework

[burgholzer]

Description

This tiny PR simplifies some details in the ECC framework Qiskit wrapper.

Checklist:

• The pull request only contains commits that are related to it.
• I have added appropriate tests and documentation.
• I have made sure that all CI jobs on GitHub pass.
• The pull request introduces no new warnings and follows the project's style guidelines.

[codecov]

Codecov Report

Merging #119 (cdce7ef) into main (2dd7a17) will decrease coverage by 0.1%.
The diff coverage is 100.0%.

@@           Coverage Diff           @@
##            main    #119     +/-   ##
=======================================
- Coverage   85.6%   85.6%   -0.1%     
=======================================
  Files         20      20             
  Lines       1364    1362      -2     
  Branches     190     190             
=======================================
- Hits        1168    1166      -2     
  Misses       196     196             

Flag	Coverage Δ
cpp	79.5% <ø> (ø)
python	97.2% <100.0%> (-0.1%)	⬇️

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Impacted Files	Coverage Δ
mqt/qecc/ecc_qiskit_wrapper.py	97.8% <100.0%> (-0.1%)	⬇️