Cleanup: Enforce keyword-only session in db_cleanup

[Gautam-Bharadwaj]

Enforce keyword-only session parameters in db_cleanup utility functions and update tests to adhere to Airflow 3 standards.

---

Was generative AI tooling used to co-author this PR?

• Yes

---

• Read the Pull Request Guidelines for more information. Note: commit author/co-author name and email in commits become permanently public when merged.
• For fundamental code changes, an Airflow Improvement Proposal (AIP) is needed.
• When adding dependency, check compliance with the ASF 3rd Party License Policy.
• For significant user-facing changes create newsfragment: {pr_number}.significant.rst, in airflow-core/newsfragments. You can add this file in a follow-up commit after the PR is created so you know the PR number.

[potiuk]

@Gautam-Bharadwaj This PR has been converted to draft because it does not yet meet our Pull Request quality criteria.

Issues found:

• ❌ Pre-commit / static checks: Failing: CI image checks / Static checks. Run prek run --from-ref main locally to find and fix issues. See Pre-commit / static checks docs.
• ❌ mypy (type checking): Failing: CI image checks / MyPy checks (mypy-providers). Run prek --stage manual mypy-providers --all-files locally to reproduce. You need breeze ci-image build --python 3.10 for Docker-based mypy. See mypy (type checking) docs.
• ❌ Other failing CI checks: Failing: check-newsfragment-pr-number. Run prek run --from-ref main locally to reproduce. See static checks docs.

Note: Your branch is 10 commits behind main. Some check failures may be caused by changes in the base branch rather than by your PR. Please rebase your branch and push again to get up-to-date CI results.

What to do next:

• The comment informs you what you need to do.
• Fix each issue, then mark the PR as "Ready for review" in the GitHub UI - but only after making sure that all the issues are fixed.
• There is no rush — take your time and work at your own pace. We appreciate your contribution and are happy to wait for updates.
• Maintainers will then proceed with a normal review.

Converting a PR to draft is not a rejection — it is an invitation to bring the PR up to the project's standards so that maintainer review time is spent productively. There is no rush — take your time and work at your own pace. We appreciate your contribution and are happy to wait for updates. If you have questions, feel free to ask on the Airflow Slack.