Change calculation of actorsytem pool usage

[kruall]

Changelog entry

Since Usage is calculated based on CurrentThreadCount, it can continuously display high values, even though there are still free cores available for thread pool expansion. We changed the calculation of usage to be based on PotentialMaxThreadCount.

Changelog category

• Not for changelog (changelog entry is not required)

Additional information

...

[github-actions]

⚪ 2024-07-03 16:55:38 UTC Pre-commit check for 3918409 has started.
⚪ 2024-07-03 16:58:51 UTC Build linux-x86_64-release-asan is running...
🟢 2024-07-03 17:28:26 UTC Build successful.
⚪ 2024-07-03 17:28:44 UTC Tests are running...
🔴 2024-07-03 19:24:51 UTC Some tests failed, follow the links below.

Test history | Test log

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
10967	10389	0	80	324	174

🟢 2024-07-03 19:25:33 UTC ydbd size 5.3 GiB changed* by -98.1 MiB, which is <= 0 Bytes vs main: OK

ydbd size dash	main: bd87563	merge: 3918409	diff	diff %
ydbd size	5 814 908 560 Bytes	5 712 085 408 Bytes	-98.1 MiB	-1.768%
ydbd stripped size	1 247 931 016 Bytes	1 235 278 632 Bytes	-12.1 MiB	-1.014%

^{*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]

⚪ 2024-07-03 17:07:20 UTC Pre-commit check for 3918409 has started.
⚪ 2024-07-03 17:10:05 UTC Build linux-x86_64-release-clang14 is running...
🟢 2024-07-03 17:19:17 UTC Build successful.

[github-actions]

⚪ 2024-07-03 17:10:50 UTC Pre-commit check for 3918409 has started.
⚪ 2024-07-03 17:13:46 UTC Build linux-x86_64-relwithdebinfo is running...
🟢 2024-07-03 17:52:02 UTC Build successful.
⚪ 2024-07-03 17:52:19 UTC Tests are running...
🔴 2024-07-03 19:44:51 UTC Some tests failed, follow the links below.

Test history | Test log

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
39430	34232	0	1	5186	11

🟢 2024-07-03 19:45:21 UTC ydbd size 8.2 GiB changed* by -144.9 MiB, which is <= 0 Bytes vs main: OK

ydbd size dash	main: bd87563	merge: 3918409	diff	diff %
ydbd size	8 926 807 928 Bytes	8 774 851 232 Bytes	-144.9 MiB	-1.702%
ydbd stripped size	486 814 568 Bytes	482 674 600 Bytes	-3.9 MiB	-0.850%

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