feat: make the QA/QC tool compatible with the newly migrated LéXPLORE repositories

[hsolleder]

The LéXPLORE repositories have been migrated away from Renku GitLab and to GitHub: here. The QA/QC pipeline developed needs to be adjusted to redirect to GitHub. This includes, for instance,

• Logging in via GitHub
• Checking the user's permissions to submit an issue via GitHub
• Creating the issues in the GitHub repositories