fix: remove duplicate ts type

Author: tangjinzhou

types/form/form.d.ts

@@ -143,13 +143,6 @@ declare interface FieldDecoratorOptions {
    */
   normalize?: (value: any, prevValue: any, allValues: any) => any;
 
-  /**
-   * Keep the field even if field removed
-   * @default false
-   * @type boolean
-   */
-  preserve?: boolean;
-
   /**
    * Includes validation rules. Please refer to "Validation Rules" part for details.
    * @default n/a