Unlink named semaphores after opening them

[kazarmy]

Your checklist for this pull request

• I've read the guidelines for contributing to this repository
• I made sure to follow the project's coding style
• I've documented or updated the documentation of every function and struct this PR changes. If not so I've explained why.
• I've added tests that prove my fix is effective or that my feature works (if possible)
• I've updated the rizin book with the relevant information (if needed)

Detailed description

This pr unlinks named semaphores after opening them so that their (unique) names are removed from the system when they are closed.

Test plan

All builds are green.

Closing issues

...

[wargio]

LGTM