don't check actor system Send() result

[lll-phill-lll]

Changelog entry

Checking the result of Send() is not recommended. Especially while using TrackUndelivered&
So, I remove it in this pr
...

Changelog category

• Not for changelog (changelog entry is not required)

Description for reviewers

...

[github-actions]

🟢 2025-07-10 11:15:42 UTC The validation of the Pull Request description is successful.

[github-actions]

⚪ 2025-07-10 09:35:00 UTC Pre-commit check linux-x86_64-relwithdebinfo for 0e41b2e has started.
⚪ 2025-07-10 09:35:12 UTC Artifacts will be uploaded here
⚪ 2025-07-10 09:38:29 UTC ya make is running...
🟡 2025-07-10 10:46:10 UTC Some tests failed, follow the links below. Going to retry failed tests...

Test history | Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
36927	34178	0	3	2701	45

⚪ 2025-07-10 10:49:24 UTC ya make is running... (failed tests rerun, try 2)
🟢 2025-07-10 11:03:16 UTC Tests successful.

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

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
255 (only retried tests)	217	0	0	0	38

🟢 2025-07-10 11:03:27 UTC Build successful.
🟢 2025-07-10 11:03:49 UTC ydbd size 2.2 GiB changed* by -3.9 KiB, which is <= 0 Bytes vs main: OK

ydbd size dash	main: c9ee256	merge: 0e41b2e	diff	diff %
ydbd size	2 390 534 128 Bytes	2 390 530 152 Bytes	-3.9 KiB	-0.000%
ydbd stripped size	500 046 056 Bytes	500 045 544 Bytes	-512 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]

⚪ 2025-07-10 09:35:15 UTC Pre-commit check linux-x86_64-release-asan for 0e41b2e has started.
⚪ 2025-07-10 09:35:41 UTC Artifacts will be uploaded here
⚪ 2025-07-10 09:39:43 UTC ya make is running...
🟡 2025-07-10 11:31:23 UTC Some tests failed, follow the links below. This fail is not in blocking policy yet

Test history | Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
14515	13936	0	326	224	29

🟢 2025-07-10 11:32:41 UTC Build successful.
🟢 2025-07-10 11:33:14 UTC ydbd size 3.9 GiB changed* by -7.5 KiB, which is <= 0 Bytes vs main: OK

ydbd size dash	main: c9ee256	merge: 0e41b2e	diff	diff %
ydbd size	4 203 699 456 Bytes	4 203 691 744 Bytes	-7.5 KiB	-0.000%
ydbd stripped size	1 456 179 160 Bytes	1 456 177 560 Bytes	-1.6 KiB	-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}