fix: remove memory leak in `library_sort.cpp`

[vil02]

Description of Change

There is a memory leak in library_sort.cpp. This PR fixes it.

Checklist

• [x] Added description of change
• [x] PR title follows semantic commit guidelines
• [x] Search previous suggestions before making a new one, as yours may be a duplicate.
• [x] I acknowledge that all my contributions will be made under the project's license.

Notes: Remove memory leak in library_sort.cpp.

[github-actions[bot]]

This pull request has been automatically marked as abandoned because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[vil02]

@Panquesito7, @realstealthninja: please dont-close.