releases: fix table format for v8.1 release notes (#19338) (#19341)

releases/release-8.1.0.md

@@ -173,8 +173,7 @@ Compared with the previous LTS 7.5.0, 8.1.0 includes new features, improvements,
 
 | Variable name | Change type | Description |
 |--------|------------------------------|------|
-| [`tidb_enable_telemetry`](/system-variables.md#tidb_enable_telemetry-new-in-v402-and-deprecated-in-v810) | Deprecated | Starting from v8.1.0, the telemetry feature in TiDB is removed, and this variable is no longer functional. It is retained solely for compatibility with earlier versions.
- |
+| [`tidb_enable_telemetry`](/system-variables.md#tidb_enable_telemetry-new-in-v402-and-deprecated-in-v810) | Deprecated | Starting from v8.1.0, the telemetry feature in TiDB is removed, and this variable is no longer functional. It is retained solely for compatibility with earlier versions. |
 | [`tidb_auto_analyze_ratio`](/system-variables.md#tidb_auto_analyze_ratio) | Modified | Changes the value range from `[0, 18446744073709551615]` to `(0, 1]`. |
 | [`tidb_enable_dist_task`](/system-variables.md#tidb_enable_dist_task-new-in-v710) | Modified | Changes the default value from `OFF` to `ON`. This means that Distributed eXecution Framework (DXF) is enabled by default, which fully utilizes the resources of the TiDB cluster and greatly improves the performance of `ADD INDEX` and `IMPORT INTO` tasks. If you want to upgrade a cluster with the DXF enabled to v8.1.0 or later, disable the DXF (by setting `tidb_enable_dist_task` to `OFF`) before the upgrade, which avoids `ADD INDEX` operations during the upgrade causing data index inconsistency. After the upgrade, you can manually enable the DXF. |
 | [`tidb_service_scope`](/system-variables.md#tidb_service_scope-new-in-v740) | Modified | Changes the optional value from `""` or `background` to a string with a length of up to 64 characters, which enables you to control the service scope of each TiDB node more flexibly. Valid characters include digits `0-9`, letters `a-zA-Z`, underscores `_`, and hyphens `-`. The Distributed eXecution Framework (DXF) determines which TiDB nodes can be scheduled to execute distributed tasks based on the value of this variable. For specific rules, see [Task scheduling](/tidb-distributed-execution-framework.md#task-scheduling). |