feat: set selectedRole as required when creating a new user (#5697)

#### What type of PR is this?

/kind improvement
/area ui

#### Which issue(s) this PR fixes:

Fixes #5677 

#### Does this PR introduce a user-facing change?

```release-note
将新建用户的表单中的角色设置设为必填
```

ui/console-src/modules/system/users/components/UserCreationModal.vue

@@ -163,6 +163,7 @@ const handleCreateUser = async () => {
         v-model="selectedRole"
         :label="$t('core.user.grant_permission_modal.fields.role.label')"
         type="roleSelect"
+        validation="required"
       ></FormKit>
       <FormKit
         v-model="formState.bio"