[FLINK-36681][mysql-cdc][docs] Fix the wrong chunks splitting query in incremental snapshot reading section

This closes  apache#3703.

Author: herunkang2018

docs/content.zh/docs/connectors/flink-sources/mysql-cdc.md

@@ -581,7 +581,7 @@ MySQL CDC Source 使用主键列将表划分为多个分片（chunk）。 默认
  [100, +∞)
 ```
 
-对于其他主键列类型， MySQL CDC Source 将以下形式执行语句： `SELECT MAX(STR_ID) AS chunk_high FROM (SELECT * FROM TestTable WHERE STR_ID > 'uuid-001' limit 25)` 来获得每个区块的低值和高值，
+对于其他主键列类型， MySQL CDC Source 将以下形式执行语句： `SELECT MAX(STR_ID) AS chunk_high FROM (SELECT * FROM TestTable WHERE STR_ID > 'uuid-001' ORDER BY STR_ID ASC LIMIT 25)` 来获得每个区块的低值和高值，
 分割块集如下所示：
 
  ```

docs/content/docs/connectors/flink-sources/mysql-cdc.md

@@ -612,7 +612,7 @@ and the table option `scan.incremental.snapshot.chunk.size` value is `25`, the t
  [100, +∞)
 ```
 
-For other primary key column type, MySQL CDC Source executes the statement in the form of `SELECT MAX(STR_ID) AS chunk_high FROM (SELECT * FROM TestTable WHERE STR_ID > 'uuid-001' limit 25)` to get the low and high value for each chunk, 
+For other primary key column type, MySQL CDC Source executes the statement in the form of `SELECT MAX(STR_ID) AS chunk_high FROM (SELECT * FROM TestTable WHERE STR_ID > 'uuid-001' ORDER BY STR_ID ASC LIMIT 25)` to get the low and high value for each chunk, 
 the splitting chunks set would be like:
 
  ```