Collect credentials from the end user when creating a new issue

[zimeg]

Type of change

• [ ] New sample
• [x] New feature
• [ ] Bug fix
• [x] Documentation

Summary

This PR changes the credential_source from DEVELOPER to END_USER to perform actions as the individual invoking the "Create new issue" workflow instead of from the shared developer token.

Requirements

• [x] I’ve checked my submission against the Samples Checklist to ensure it complies with all standards
• [x] I have ensured the changes I am contributing align with existing patterns and have tested and linted my code
• [x] I've read and agree to the Code of Conduct