Use ; as IGN_CONFIG_PATH delimiter on windows

[scpeters]

🦟 Bug fix

Fixes #43

Summary

The ign tool looks in the IGN_CONFIG_PATH environment variable for a : delimited list of paths to search for ignition command files. Since Windows paths have : (for example C:\), this logic incorrectly splits windows paths.

Checklist

• [X] Signed all commits for DCO
• [ ] Added tests
• [ ] Updated documentation (as needed)
• [ ] Updated migration guide (as needed)
• [ ] codecheck passed (See contributing)
• [ ] All tests passed (See test coverage)
• [ ] While waiting for a review on your PR, please help review another open pull request to support the maintainers

Note to maintainers: Remember to use Squash-Merge