IBX-4741: Migration from TRAVIS_GITHUB_TOKEN

[ibexa-yuna]

Question	Answer
JIRA issue	IBX-4741
Type	improvement
Target Ibexa version	v4.x+
BC breaks	no
Doc needed	yes (already done)

This will migrate from the old setup generator step in a release workflow.
For specifics see the wiki: https://ibexa.atlassian.net/wiki/spaces/ENG/pages/12713999/Migrating+from+TRAVIS+GITHUB+TOKEN

Merge up path: 4.3 -> master

Note: The same changelist will be applied to other meta-repositories i.e. oss, content and experience.

Checklist:

• Provided PR description.
• Tested the solution manually.
• Checked that the target branch is set correctly.
• Asked for a review (ping @ibexa/engineering).