[24.1] Fix copying workflow with subworkflow step for step that you own

[mvdbeek]

Fixes https://sentry.galaxyproject.org/share/issue/b115ec00f2e3469c83c8793c0a7d50bb/ which fixes the currently blocked IWC workflow deployment script

How to test the changes?

(Select all options that apply)

• I've included appropriate automated tests.
• This is a refactoring of components with existing test coverage.
• Instructions for manual testing are as follows:
  1. [add testing steps and prerequisites here if you didn't write automated tests covering all your changes]

License

• I agree to license these and all my past contributions to the core galaxy codebase under the MIT license.