🐛 Prevent manually declared layout obstructions to be cleared by the application of Yen's Algorithm

[marcelwa]

Description

When an obstruction_layout with manually declared obstructions is fed into yen_k_shortest_paths, these obstructions are invalidated during the algorithm's run. This PR fixes the issue.

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.

[github-actions]

clang-tidy review says "All clean, LGTM! 👍"

[codecov]

Codecov Report

Merging #143 (b4ff0cb) into main (9479232) will increase coverage by 0.01%.
The diff coverage is 100.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #143      +/-   ##
==========================================
+ Coverage   93.92%   93.94%   +0.01%     
==========================================
  Files          75       75              
  Lines        7017     7032      +15     
==========================================
+ Hits         6591     6606      +15     
  Misses        426      426              

Impacted Files	Coverage Δ
...ction/algorithms/path_finding/k_shortest_paths.hpp	100.00% <100.00%> (ø)
include/fiction/layouts/obstruction_layout.hpp	100.00% <100.00%> (ø)

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