use availability_period in the db/tests/stress/topic test

[ubyte]

Changelog entry

...

Changelog category

• Not for changelog (changelog entry is not required)

Description for reviewers

LOGBROKER-9999

[github-actions]

🟢 2025-10-08 18:40:44 UTC The validation of the Pull Request description is successful.

[github-actions]

⚪ 2025-10-08 18:43:20 UTC Pre-commit check linux-x86_64-relwithdebinfo for da5542b has started.
⚪ 2025-10-08 18:45:59 UTC Artifacts will be uploaded here
⚪ 2025-10-08 18:48:37 UTC ya make is running...
🟢 2025-10-08 18:51:55 UTC Tests successful.

Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
16	16	0	0	0	0

🟢 2025-10-08 18:51:58 UTC Build successful.
🟢 2025-10-08 18:52:09 UTC ydbd size 2.3 GiB changed* by 0 Bytes, which is <= 0 Bytes vs main: OK

ydbd size dash	main: 69a3522	merge: da5542b	diff	diff %
ydbd size	2 418 031 144 Bytes	2 418 031 144 Bytes	0 Bytes	0.000%
ydbd stripped size	515 031 176 Bytes	515 031 176 Bytes	0 Bytes	0.000%

^{*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]

⚪ 2025-10-08 18:44:38 UTC Pre-commit check linux-x86_64-release-asan for da5542b has started.
⚪ 2025-10-08 18:44:53 UTC Artifacts will be uploaded here
⚪ 2025-10-08 18:47:42 UTC ya make is running...
🟡 2025-10-08 18:52:23 UTC Some tests failed, follow the links below. This fail is not in blocking policy yet

Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
10	9	0	1	0	0

🟢 2025-10-08 18:52:26 UTC Build successful.
🟢 2025-10-08 18:52:42 UTC ydbd size 3.7 GiB changed* by -96 Bytes, which is <= 0 Bytes vs main: OK

ydbd size dash	main: 69a3522	merge: da5542b	diff	diff %
ydbd size	4 021 828 736 Bytes	4 021 828 640 Bytes	-96 Bytes	-0.000%
ydbd stripped size	1 494 064 512 Bytes	1 494 064 448 Bytes	-64 Bytes	-0.000%

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