Fix typo in enable_block_offset_column setting description

[lucleray]

The description for enable_block_offset_column incorrectly says _block_number instead of _block_offset (copy-paste from the enable_block_number_column setting above).

Changelog category (leave one):

• Documentation (changelog entry is not required)

Changelog entry (a user-readable short description of the changes that goes into CHANGELOG.md):

(N/A since it's a documentation change)

Documentation entry for user-facing changes

• Documentation is written (mandatory for new features)

[CLAassistant]

All committers have signed the CLA.

[clickhouse-gh]

Workflow [PR], commit [2a1716a]

Summary: ❌

job_name	test_name	status	info	comment
Stateless tests (amd_asan_ubsan, distributed plan, parallel, 1/2)		failure
	03632_skip_indices_logged_in_query_log	FAIL	cidb
Stateless tests (amd_msan, WasmEdge, parallel, 1/2)		failure
	03632_skip_indices_logged_in_query_log	FAIL	cidb
	04039_skip_index_query_log_actually_applied	FAIL	cidb
Stateless tests (amd_debug, distributed plan, s3 storage, parallel)		failure
	03632_skip_indices_logged_in_query_log	FAIL	cidb
	04039_skip_index_query_log_actually_applied	FAIL	cidb
Stateless tests (arm_binary, parallel)		failure
	03632_skip_indices_logged_in_query_log	FAIL	cidb
	04039_skip_index_query_log_actually_applied	FAIL	cidb
Stress test (amd_tsan)		failure
	Hung check failed, possible deadlock found	FAIL	cidb
Stress test (amd_msan)		failure
	Hung check failed, possible deadlock found	FAIL	cidb

---

AI Review

Summary

This PR fixes a typo in the enable_block_offset_column setting description in MergeTree settings, changing an incorrect reference to _block_number into _block_offset. The change is correct, low risk, and improves user-facing documentation clarity without altering behavior.

ClickHouse Rules

Item	Status	Notes
Deletion logging	➖
Serialization versioning	➖
Core-area scrutiny	✅
No test removal	✅
Experimental gate	➖
No magic constants	✅
Backward compatibility	✅
SettingsChangesHistory.cpp	➖
PR metadata quality	✅
Safe rollout	✅
Compilation time	✅

Final Verdict

• Status: ✅ Approve

[clickhouse-gh]

LLVM Coverage Report

Metric	Baseline	Current	Δ
Lines	84.10%	84.10%	+0.00%
Functions	24.60%	24.50%	-0.10%
Branches	76.70%	76.70%	+0.00%

Changed lines: 100.00% (7/7) · Uncovered code

Full report · Diff report

[lucleray]

@alexey-milovidov Do you know if the CI failures are related to my PR ? As far as I could tell it's unrelated, but happy to make more changes if I need to. And thanks for the review!