The workflow does not quote `**/*.md`, so bash will handle the globbing, which does not support the recursive pattern `**`.
After quoting, bash will pass `**/*.md` to lychee, which will find all markdown files in the repository.
This will hopefully reduce the false reports due to some unreliable hosters.
* Fixes broken links in memory_management/README.md
* Fixes broken link in audio_comp_sci/README.md
* Fixes broken link in security/README.md
* Fixes broken links in garbage_collection/README.md
* Increase max retries for lychee