HIVE-29752: Docker publish workflow in forks should push to the fork's namespace

[deniskuzZ]

What changes were proposed in this pull request?

Derive the Docker Hub namespace from github.repository_owner instead of the hardcoded apache default

Why are the changes needed?

The workflow defaulted the push namespace to apache regardless of which repository/fork it ran in.

Does this PR introduce any user-facing change?

No

How was this patch tested?

[zabetak]

Changes LGTM, will perform a test run of the action on my fork and if everything runs fine will submit the final approval.

[zabetak]

Test action on fork repository is in progress: https://github.com/zabetak/hive/actions/runs/29935070044/job/88974409354

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[okumin]

The intention sounds good, but it is not always the case that a GitHub user abc has a DockerHub repository abc. As of today, it is probably not an immediate problem, so it is okay to revisit it when someone hits the issue, though

[zabetak]

The test action in https://github.com/zabetak/hive/actions/runs/29935070044/job/88974409354 completed successfully and pushed the nightly images to the users (zabetak) namespace in https://hub.docker.com/r/zabetak/hive/tags.