[Fix][MySQL]: Fix MySqlTypeConverter could not be instantiated (#6781)

Fix `MySqlTypeConverter` could not be instantiated because  `ServiceLoader` Should have a NonArgsContractor.

seatunnel-connectors-v2/connector-jdbc/src/main/java/org/apache/seatunnel/connectors/seatunnel/jdbc/internal/dialect/mysql/MySqlTypeConverter.java

@@ -109,6 +109,10 @@ public MySqlTypeConverter(MySqlVersion version) {
         this.version = version;
     }
 
+    public MySqlTypeConverter() {
+        this(MySqlVersion.V_5_7);
+    }
+
     @Override
     public String identifier() {
         return DatabaseIdentifier.MYSQL;