Replace RemovedInAirflow3Warning by DeprecationWarning in warnings captures test dags

[Taragolis]

Originally this test raise RemovedInAirflow3Warning which might have a side effect in the other tests which are loaded entire test dag folder, replace it for something which we do not prohibit in our tests.

It also should fix one case (tests/cli/commands/test_dag_command.py::TestCliDags::test_backfill_treat_dag_as_regex_deprecation) in #39450 which started failed due to changes in pytest.warns in 8.0, it now reraise unmatched warnings in the end of context manager

❯ pytest tests/cli/commands/test_dag_command.py::TestCliDags::test_backfill_treat_dag_as_regex_deprecation
====================================================================================================== test session starts ======================================================================================================
platform linux -- Python 3.9.9, pytest-8.2.0, pluggy-1.5.0 -- /home/taragolis/.pyenv/versions/3.9.9/envs/airflow-env/bin/python3.9
cachedir: .pytest_cache
rootdir: /home/taragolis/Projects/common/airflow
configfile: pyproject.toml
plugins: mock-3.12.0, rerunfailures-12.0, anyio-4.0.0, time-machine-2.13.0, asyncio-0.21.1, forked-1.4.0, icdiff-0.8, timeouts-1.2.1, instafail-0.5.0, xdist-3.3.1, cov-4.1.0, requests-mock-1.11.0, httpx-0.21.3
asyncio: mode=strict
setup timeout: 0.0s, execution timeout: 0.0s, teardown timeout: 0.0s
collected 1 item                                                                                                                                                                                                                

tests/cli/commands/test_dag_command.py::TestCliDags::test_backfill_treat_dag_as_regex_deprecation PASSED                                                                                                                  [100%]
============================================================================================= Warning summary. Total: 8, Unique: 2 ==============================================================================================
tests: total 8, unique 2
  runtest: total 8, unique 2
Warnings saved into /home/taragolis/Projects/common/airflow/tests/warnings.txt file.

======================================================================================================= 1 passed in 4.06s =======================================================================================================

---

^ Add meaningful description above
Read the Pull Request Guidelines for more information.
In case of fundamental code changes, an Airflow Improvement Proposal (AIP) is needed.
In case of a new dependency, check compliance with the ASF 3rd Party License Policy.
In case of backwards incompatible changes please leave a note in a newsfragment file, named {pr_number}.significant.rst or {issue_number}.significant.rst, in newsfragments.