Update CHANGELOG.md for stable-25-3:2025-10-12

[ydbot]

This PR updates the CHANGELOG.md file for 2025-10-12.

[github-actions]

🟢 2025-10-12 00:13:54 UTC The validation of the Pull Request description is successful.

[github-actions]

⚪ 2025-10-12 00:19:08 UTC Pre-commit check linux-x86_64-relwithdebinfo for db78678 has started.
⚪ 2025-10-12 00:19:22 UTC Artifacts will be uploaded here
⚪ 2025-10-12 00:21:59 UTC ya make is running...
🟢 2025-10-12 00:22:04 UTC Tests successful.

Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
0	0	0	0	0	0

🟢 2025-10-12 00:22:10 UTC Build successful.

[github-actions]

⚪ 2025-10-12 00:25:32 UTC Pre-commit check linux-x86_64-release-asan for db78678 has started.
⚪ 2025-10-12 00:25:36 UTC Artifacts will be uploaded here
⚪ 2025-10-12 00:28:09 UTC ya make is running...
🟢 2025-10-12 00:28:14 UTC Tests successful.

Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
0	0	0	0	0	0

🟢 2025-10-12 00:28:20 UTC Build successful.