TiDB DM returned ERROR when connect MySQL 8.4

## Feature Request

**Is your feature request related to a problem? Please describe:**
I have deployed a TiDB cluster (v8.5.0) and Dm cluster (v8.5.0). After connect the MySQL source with DM we cannot start the DM task due to the compatibility issue. below is the error.

"errors": [
{
"severity": "fail",
"short_error": "Message: fail to get random server id for relay reader: database driver error, RawCause: Error 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'SLAVE HOSTS' at line 1"
}
],

"errors": [
{
"severity": "fail",
"short_error": "Message: database driver error, RawCause: Error 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'MASTER STATUS' at line 1"
}
],

From mysql 8.4 some of the syntax changed in the earlier versions. As TiDB compatible with MySQL 8.0 it returning error.

**Describe the feature you'd like:**
We request official support for MySQL 8.4 in TiDB and TiDB - DM, including handling new or changed SQL syntax to ensure smooth data migration tasks from MySQL 8.4 to TiDB.

**Describe alternatives you've considered:**
The DM is a core tool for syncing MySQL to TiDB with minimal downtime, a batch update to support MySQL 8.4 syntax in DM would be highly beneficial.

**Teachability, Documentation, Adoption, Migration Strategy:**
TiDB DM is for real-time synchronization between MySQL and TiDB, especially for minimizing downtime during migrations.
Ensuring DM compatibility with MySQL 8.4 will:

Simplify adoption for users upgrading MySQL to 8.4

Reduce errors during task creation