2.2版本的XA模式不支持达梦数据库

### Check Ahead

- [x] I have searched the [issues](https://github.com/seata/seata/issues) of this repository and believe that this is not a duplicate.

### Ⅰ. Issue Description

2.2版本的XA模式不支持达梦数据库

### Ⅱ. Describe what happened

`Caused by: java.sql.SQLException: create xaConnection error
at org.apache.seata.rm.datasource.util.XAUtils.createXAConnection(XAUtils.java:76)
at org.apache.seata.rm.datasource.util.XAUtils.createXAConnection(XAUtils.java:48)
at org.apache.seata.rm.datasource.xa.DataSourceProxyXA.getConnectionProxyXA(DataSourceProxyXA.java:112)
at org.apache.seata.rm.datasource.xa.DataSourceProxyXA.getConnectionProxy(DataSourceProxyXA.java:101)
at org.apache.seata.rm.datasource.xa.DataSourceProxyXA.getConnection(DataSourceProxyXA.java:88)
... 83 common frames omitted
Caused by: java.sql.SQLException: xa not support dbType: dm
at org.apache.seata.rm.datasource.util.XAUtils.createXAConnection(XAUtils.java:73)
... 87 common frames omitted`

### Ⅲ. Describe what you expected to happen

XA模式有计划支持达梦数据库吗

### Ⅳ. How to reproduce it (as minimally and precisely as possible)

_No response_

### Ⅴ. Anything else we need to know?

_No response_

### Ⅵ. Environment

seata 2.2
springboot 2.7.18
达梦8.1

Start with the stack trace locations in rm-datasource/src/main/java/org/apache/seata/rm/datasource/util/XAUtils.java and DataSourceProxyXA.java, especially createXAConnection. Compare the existing XA database handling and related tests, then confirm the expected Dameng 8.1 behavior and support scope. Done means XA mode works with Dameng and the relevant regression coverage passes.

Written by the indexing model from the issue text.