KONFLUX-1611: Add labels, licenses & user to Dockerfile

[pastequo]

• Add labels
• Add default user
• Add licenses under /licenses/

Requirements come from https://docs.redhat.com/en/documentation/red_hat_software_certification/2024/html-single/red_hat_openshift_software_certification_policy_guide/index#additional_resources and would prevent us from releasing an image (we have an exception for "based_on_ubi image")

List all the issues related to this PR

• [ ] New Feature
• [ ] Enhancement
• [ ] Bug fix
• [ ] Tests
• [ ] Documentation
• [x] CI/CD

What environments does this code impact?

• [ ] Automation (CI, tools, etc)
• [x] Cloud
• [ ] Operator Managed Deployments
• [ ] None

How was this code tested?

• [ ] assisted-test-infra environment
• [ ] dev-scripts environment
• [ ] Reviewer's test appreciated
• [ ] Waiting for CI to do a full test run
• [ ] Manual (Elaborate on how it was tested)
• [x] No tests needed

Checklist

• [x] Title and description added to both, commit and PR.
• [x] Relevant issues have been associated (see CONTRIBUTING guide)
• [x] This change does not require a documentation update (docstring, docs, README, etc)
• [x] Does this change include unit-tests (note that code changes require unit-tests)

Reviewers Checklist

• Are the title and description (in both PR and commit) meaningful and clear?
• Is there a bug required (and linked) for this change?
• Should this PR be backported?