Fix test example

[maximyurchuk]

Do not use setup_class -- it is a bad practice

[Copilot]

Pull Request Overview

This PR updates the test setup by replacing the legacy class-level setup and teardown methods with a pytest fixture using autouse, aligning the tests with current best practices.

• Replaced the @classmethod-based setup and teardown with a pytest fixture that uses yield for teardown.
• Removed the separate teardown_class method to streamline setup and cleanup.

Comments suppressed due to low confidence (1)

ydb/tests/example/test_example.py:17

• [nitpick] Consider renaming the fixture from 'setup_class' to a name that better reflects its usage as a pytest fixture (e.g., 'cluster_setup') to avoid confusion with the legacy setup_class pattern.

@pytest.fixture(autouse=True)

[github-actions]

🟢 2025-06-11 13:20:11 UTC The validation of the Pull Request description is successful.

[github-actions]

⚪ 2025-06-11 13:27:18 UTC Pre-commit check linux-x86_64-release-asan for 5424a98 has started.
⚪ 2025-06-11 13:27:44 UTC Artifacts will be uploaded here
⚪ 2025-06-11 13:30:55 UTC ya make is running...
🟢 2025-06-11 13:33:13 UTC Tests successful.

Test history | Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
7	6	0	0	1	0

🟢 2025-06-11 13:33:20 UTC Build successful.
🟡 2025-06-11 13:33:34 UTC ydbd size 3.9 GiB changed* by +104.3 KiB, which is >= 100.0 KiB vs main: Warning

ydbd size dash	main: 8e0f901	merge: 5424a98	diff	diff %
ydbd size	4 167 775 264 Bytes	4 167 882 080 Bytes	+104.3 KiB	+0.003%
ydbd stripped size	1 445 699 288 Bytes	1 445 739 960 Bytes	+39.7 KiB	+0.003%

^{*please be aware that the difference is based on comparing your commit and the last completed build from the post-commit, check comparation}

[github-actions]

⚪ 2025-06-11 13:27:45 UTC Pre-commit check linux-x86_64-relwithdebinfo for 5424a98 has started.
⚪ 2025-06-11 13:28:00 UTC Artifacts will be uploaded here
⚪ 2025-06-11 13:31:08 UTC ya make is running...
🟢 2025-06-11 13:32:51 UTC Tests successful.

Test history | Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
9	8	0	0	1	0

🟢 2025-06-11 13:32:58 UTC Build successful.
🟢 2025-06-11 13:33:08 UTC ydbd size 2.2 GiB changed* by +40.2 KiB, which is < 100.0 KiB vs main: OK

ydbd size dash	main: cac7377	merge: 5424a98	diff	diff %
ydbd size	2 369 797 552 Bytes	2 369 838 720 Bytes	+40.2 KiB	+0.002%
ydbd stripped size	497 038 888 Bytes	497 045 320 Bytes	+6.3 KiB	+0.001%

^{*please be aware that the difference is based on comparing your commit and the last completed build from the post-commit, check comparation}