Set level 15 for OTEL tracing header by default

[va-kuznecov]

Changelog entry

...

Changelog category

• New feature
• Experimental feature
• Improvement
• Performance improvement
• User Interface
• Bugfix
• Backward incompatible change
• Documentation (changelog entry is not required)
• Not for changelog (changelog entry is not required)

Description for reviewers

...

[github-actions]

⚪ 2025-09-26 15:15:30 UTC Pre-commit check for 3dbc94e has started.
⚪ 2025-09-26 15:18:07 UTC Build linux-x86_64-relwithdebinfo is running...
🟢 2025-09-26 16:20:55 UTC Build successful.
⚪ 2025-09-26 16:21:10 UTC Tests are running...
🟢 2025-09-26 17:47:42 UTC Tests successful.

Test history | Test log

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
15573	14199	0	0	1292	82

🟢 2025-09-26 17:48:27 UTC ydbd size 8.3 GiB changed* by -16 Bytes, which is <= 0 Bytes vs stream-nb-24-4: OK

ydbd size dash	stream-nb-24-4: 824a5fd	merge: 3dbc94e	diff	diff %
ydbd size	8 952 419 224 Bytes	8 952 419 208 Bytes	-16 Bytes	-0.000%
ydbd stripped size	487 383 784 Bytes	487 383 784 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]

⚪ 2025-09-26 15:15:30 UTC Pre-commit check for 3dbc94e has started.
⚪ 2025-09-26 15:18:09 UTC Build linux-x86_64-release-asan is running...
🟢 2025-09-26 16:00:47 UTC Build successful.
⚪ 2025-09-26 16:01:04 UTC Tests are running...
🔴 2025-09-26 18:21:53 UTC Some tests failed, follow the links below.

Test history | Test log

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
11131	10996	0	29	29	77

🟢 2025-09-26 18:22:34 UTC ydbd size 5.7 GiB changed* by -96 Bytes, which is <= 0 Bytes vs stream-nb-24-4: OK

ydbd size dash	stream-nb-24-4: 824a5fd	merge: 3dbc94e	diff	diff %
ydbd size	6 068 908 944 Bytes	6 068 908 848 Bytes	-96 Bytes	-0.000%
ydbd stripped size	1 519 639 136 Bytes	1 519 639 072 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}