Fix failing tests to work with PyTest 8.4.0

[gopidesupavan]

Body

Pytest 8.4.0 introduced some changes which are breaking tests.

ex: some of the fixtures the way we defined not complain with pytest 8.4.0

https://github.com/apache/airflow/actions/runs/15405154759/job/43346489871?pr=51279#step:6:1226

https://github.com/pytest-dev/pytest/releases/tag/8.4.0

Committer

• I acknowledge that I am a maintainer/committer of the Apache Airflow project.