fix: OPA authorization for Airflow 3

[sbernauer]

Description

Part of #640

Definition of Done Checklist

• Not all of these items are applicable to all PRs, the author should update this template to only leave the boxes in that are relevant
• Please make sure all these things are done and tick the boxes

Author

• Changes are OpenShift compatible
• CRD changes approved
• CRD documentation for all fields, following the style guide.
• Helm chart can be installed and deployed operator works
• Integration tests passed (for non trivial changes)
• Changes need to be "offline" compatible
• Links to generated (nightly) docs added
• Release note snippet added

Reviewer

• Code contains useful comments
• Code contains useful logging statements
• (Integration-)Test cases added
• Documentation added or updated. Follows the style guide.
• Changelog updated
• Cargo.toml only contains references to git tags (not specific commits or branches)

Acceptance

• Feature Tracker has been updated
• Proper release label has been added
• Links to generated (nightly) docs added
• Release note snippet added
• Add type/deprecation label & add to the deprecation schedule
• Add type/experimental label & add to the experimental features tracker

[sbernauer]

Started https://testing.stackable.tech/view/02%20Operator%20Tests%20(custom)/job/airflow-operator-it-custom/46/

[adwk67]

LGTM assuming tests are OK - thanks!

[sbernauer]

The first two test failed

        --- FAIL: kuttl/harness/logging_airflow-2.10.5_openshift-false_executor-celery (437.79s)
        --- FAIL: kuttl/harness/oidc_airflow-latest-3.0.1_openshift-false (512.55s)

which is flakiness and probably image pull problems

[lfrancke]

Please add a release note snippet in the form "Previously, this went wrong. With this release, this was fixed in the following way."

[sbernauer]

Release note

Previously, OpenPolicyAgent (OPA) authorization for Airflow 3 was not working. With this release, the operator now sets the needed env variables to make this work for Airflow 3