25-1: Fix a subtle memory leak in SendImmediateWriteResult

[snaury]

Changelog entry

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Changelog category

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Description for reviewers

There was a subtle edge case in SendImmediateWriteResult where we drop the result. Turned out this case was actually leaking the event.

Fixes #16657.

[github-actions]

🟢 2025-04-15 07:15:55 UTC The validation of the Pull Request description is successful.

[github-actions]

⚪ 2025-04-15 07:15:58 UTC Pre-commit check linux-x86_64-relwithdebinfo for 738fdad has started.
⚪ 2025-04-15 07:16:12 UTC Artifacts will be uploaded here
⚪ 2025-04-15 07:19:06 UTC ya make is running...
🟡 2025-04-15 08:16:20 UTC Some tests failed, follow the links below. Going to retry failed tests...

Details

Test history | Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
19293	17942	0	4	1215	132

⚪ 2025-04-15 08:17:53 UTC ya make is running... (failed tests rerun, try 2)
🟢 2025-04-15 08:38:45 UTC Tests successful.

Test history | Ya make output | Test bloat | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
204 (only retried tests)	76	0	0	0	128

🟢 2025-04-15 08:38:52 UTC Build successful.
🟢 2025-04-15 08:39:11 UTC ydbd size 2.1 GiB changed* by +128 Bytes, which is < 100.0 KiB vs stable-25-1: OK

ydbd size dash	stable-25-1: 6be3a09	merge: 738fdad	diff	diff %
ydbd size	2 244 539 176 Bytes	2 244 539 304 Bytes	+128 Bytes	+0.000%
ydbd stripped size	475 243 896 Bytes	475 243 960 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}

[github-actions]

⚪ 2025-04-15 07:16:02 UTC Pre-commit check linux-x86_64-release-asan for 738fdad has started.
⚪ 2025-04-15 07:16:16 UTC Artifacts will be uploaded here
⚪ 2025-04-15 07:19:13 UTC ya make is running...
🟡 2025-04-15 08:32:49 UTC Some tests failed, follow the links below. This fail is not in blocking policy yet Going to retry failed tests...

Details

Test history | Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
12032	11947	0	47	4	34

⚪ 2025-04-15 08:33:49 UTC ya make is running... (failed tests rerun, try 2)
🟡 2025-04-15 08:54:55 UTC Some tests failed, follow the links below. This fail is not in blocking policy yet Going to retry failed tests...

Details

Test history | Ya make output | Test bloat | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
135 (only retried tests)	102	0	1	2	30

⚪ 2025-04-15 08:55:04 UTC ya make is running... (failed tests rerun, try 3)
🟢 2025-04-15 09:16:26 UTC Tests successful.

Test history | Ya make output | Test bloat | Test bloat | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
58 (only retried tests)	28	0	0	0	30

🟢 2025-04-15 09:16:33 UTC Build successful.
🟢 2025-04-15 09:17:01 UTC ydbd size 3.6 GiB changed* by +304 Bytes, which is < 100.0 KiB vs stable-25-1: OK

ydbd size dash	stable-25-1: 6be3a09	merge: 738fdad	diff	diff %
ydbd size	3 904 436 784 Bytes	3 904 437 088 Bytes	+304 Bytes	+0.000%
ydbd stripped size	1 366 142 992 Bytes	1 366 143 056 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}