[Doc] fix built-in typo (#14667)

Signed-off-by: Gallardot <gallardot@apache.org>

docs/docs/en/guide/parameter/built-in.md

@@ -8,7 +8,7 @@
 | system.biz.curdate              | `${system.biz.curdate}`              | The schedule time of the daily scheduling instance, the format is `yyyyMMdd`                |
 | system.datetime                 | `${system.datetime}`                 | The schedule time of the daily scheduling instance, the format is `yyyyMMddHHmmss`          |
 | system.task.execute.path        | `${system.task.execute.path}`        | The absolute path of current executing task                                                 |
-| system.task.instance.id         | `${ssystem.task.instance.id}`        | The instance id of current task                                                             |
+| system.task.instance.id         | `${system.task.instance.id}`         | The instance id of current task                                                             |
 | system.task.definition.name     | `${system.task.definition.name}`     | The definition name of current task                                                         |
 | system.task.definition.code     | `${system.task.definition.code}`     | The definition code of current task                                                         |
 | system.workflow.instance.id     | `${system.workflow.instance.id}`     | The instance id of the workflow to which current task belongs                               |

docs/docs/zh/guide/parameter/built-in.md

@@ -8,7 +8,7 @@
 | system.biz.curdate              | `${system.biz.curdate}`              | 日常调度实例定时的定时时间，格式为 yyyyMMdd       |
 | system.datetime                 | `${system.datetime}`                 | 日常调度实例定时的定时时间，格式为 yyyyMMddHHmmss |
 | system.task.execute.path        | `${system.task.execute.path}`        | 当前任务执行的绝对路径                      |
-| system.task.instance.id         | `${ssystem.task.instance.id}`        | 当前任务实例的ID                        |
+| system.task.instance.id         | `${system.task.instance.id}`         | 当前任务实例的ID                        |
 | system.task.definition.name     | `${system.task.definition.name}`     | 当前任务所属任务定义的名称                    |
 | system.task.definition.code     | `${system.task.definition.code}`     | 当前任务所属任务定义的code                  |
 | system.workflow.instance.id     | `${system.workflow.instance.id}`     | 当前任务所属工作流实例ID                    |