25-3: Use a separate alerts_exception counter for unhandled exceptions

[snaury]

Changelog entry

...

Changelog category

• Not for changelog (changelog entry is not required)

Description for reviewers

Unhandled exceptions need a separate counter since it's a much more severe than other Broken() calls in executor.

[github-actions]

⚪ 2025-10-14 12:06:12 UTC Pre-commit check linux-x86_64-release-asan for fce6a71 has started.
⚪ 2025-10-14 12:06:26 UTC Artifacts will be uploaded here
⚪ 2025-10-14 12:10:01 UTC ya make is running...
🟡 2025-10-14 14:28:36 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?
15892	15404	0	172	295	21

🟢 2025-10-14 14:29:50 UTC Build successful.
🟢 2025-10-14 14:30:14 UTC ydbd size 3.8 GiB changed* by +6.2 KiB, which is < 100.0 KiB vs stable-25-3: OK

ydbd size dash	stable-25-3: e36ae51	merge: fce6a71	diff	diff %
ydbd size	4 046 920 776 Bytes	4 046 927 112 Bytes	+6.2 KiB	+0.000%
ydbd stripped size	1 507 602 944 Bytes	1 507 604 736 Bytes	+1.8 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}

[github-actions]

🟢 2025-10-14 12:06:27 UTC The validation of the Pull Request description is successful.

[github-actions]

⚪ 2025-10-14 12:07:09 UTC Pre-commit check linux-x86_64-relwithdebinfo for fce6a71 has started.
⚪ 2025-10-14 12:07:22 UTC Artifacts will be uploaded here
⚪ 2025-10-14 12:10:54 UTC ya make is running...
🟡 2025-10-14 13:44:31 UTC Some tests failed, follow the links below. Going to retry failed tests...

Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
38561	35879	0	11	2651	20

⚪ 2025-10-14 13:47:40 UTC ya make is running... (failed tests rerun, try 2)
🟡 2025-10-14 14:08:01 UTC Some tests failed, follow the links below. Going to retry failed tests...

Ya make output | Test bloat | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
594 (only retried tests)	573	0	1	2	18

⚪ 2025-10-14 14:08:11 UTC ya make is running... (failed tests rerun, try 3)
🔴 2025-10-14 14:30:54 UTC Some tests failed, follow the links below.

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

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
566 (only retried tests)	546	0	2	1	17

🟢 2025-10-14 14:31:03 UTC Build successful.
🟢 2025-10-14 14:31:21 UTC ydbd size 2.3 GiB changed* by +7.5 KiB, which is < 100.0 KiB vs stable-25-3: OK

ydbd size dash	stable-25-3: e36ae51	merge: fce6a71	diff	diff %
ydbd size	2 432 295 912 Bytes	2 432 303 624 Bytes	+7.5 KiB	+0.000%
ydbd stripped size	521 037 544 Bytes	521 042 216 Bytes	+4.6 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}