Update TiDB Dashboard port in access docs

Changed the default PORT value from 10261 to 10262 in both English and Chinese access-dashboard documentation to reflect the correct configuration.

Author: hfxsd

en/access-dashboard.md

@@ -48,7 +48,7 @@ In this deployment method, the `service`, `port`, and `HTTP` paths of TiDB Dashb
 
 ```shell
 export SERVICE_NAME=${cluster_name}-discovery && \
-export PORT=10261 && \
+export PORT=10262 && \
 export HTTP_PATH=/dashboard
 ```
 

zh/access-dashboard.md

@@ -46,7 +46,7 @@ spec:
 
 ```shell
 export SERVICE_NAME=${cluster_name}-discovery && \
-export PORT=10261 && \
+export PORT=10262 && \
 export HTTP_PATH=/dashboard
 ```