Change namespace separator for OpenPipelines v1

[rcannood]

While we still can

Changelog

... Describe your changes ...

Issue ticket number and link

Closes #xxxx (Replace xxxx with the GitHub issue number)

Checklist before requesting a review

• [ ] I have performed a self-review of my code

• [ ] Conforms to the Contributor's guide

• Check the correct box. Does this PR contain:

  • [ ] Breaking changes
  • [ ] New functionality
  • [ ] Major changes
  • [ ] Minor changes
  • [ ] Documentation
  • [ ] Bug fixes

• [ ] Proposed changes are described in the CHANGELOG.md

• [ ] CI tests succeed!