It appears that Ubuntu is automatically generating a file in that directory, potentially creating a backdoor option for users who choose common default credentials, such as 'admin/admin.' This could inadvertently undermine attempts to enforce private key authentication by setting 'PasswordAuthentication no' in the main '/etc/ssh/sshd_config' file, as there might be an override active in that subdirectory /etc/ssh/sshd_config.d/ without the user's awareness. Please let me know if you encounter the same files and check your systems, I've got the suspicion that this is not a one time occurrence!
What coding guideline do you use for your internal Developers? It would be interesting to see what is being used as code instructions to assure code quality, security, re-useability and many other factors which are relevant to good coding practices.
