Fix checkpid on windows

[hurricanehrndz]

Describe your changes

syscall.signal 0 does not work on windows as it is not implemented

Issue ticket number and link

Checklist

• [x] Is it a bug fix
• [ ] Is a typo/documentation fix
• [ ] Is a feature enhancement
• [ ] It is a refactor
• [ ] Created tests that fail without the change (if possible)
• [ ] Extended the README / documentation, if necessary