[typo](docs) fix docs DROP-ROLE.md (#18143)

docs/en/docs/sql-manual/sql-reference/Account-Management-Statements/DROP-ROLE.md

@@ -31,7 +31,7 @@ under the License.
 The statement user removes a role
 
 ```sql
-  DROP ROLE role1;
+  DROP ROLE [IF EXISTS] role1;
 ````
 
 Deleting a role does not affect the permissions of users who previously belonged to the role. It is only equivalent to decoupling the role from the user. The permissions that the user has obtained from the role will not change

docs/zh-CN/docs/sql-manual/sql-reference/Account-Management-Statements/DROP-ROLE.md

@@ -35,7 +35,7 @@ DROP ROLE
 语句用户删除角色
 
 ```sql
-  DROP ROLE role1;
+  DROP ROLE [IF EXISTS] role1;
 ````
 
 删除角色不会影响以前属于角色的用户的权限。 它仅相当于解耦来自用户的角色。 用户从角色获得的权限不会改变