docs(secretsmanager): doc when automaticallyAfter for RotationSchedul…

…e is 0 is wrong (#27570)

We discussed that the doc when `automaticallyAfter` for `RotationSchedule` is `Duration.days(0)` is wrong. So I modified the doc.

See the issue (#27460) and another PR (#27497 (comment)).

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packages/aws-cdk-lib/aws-secretsmanager/lib/rotation-schedule.ts

@@ -37,7 +37,7 @@ export interface RotationScheduleOptions {
    * Specifies the number of days after the previous rotation before
    * Secrets Manager triggers the next automatic rotation.
    *
-   * A value of zero will disable automatic rotation - `Duration.days(0)`.
+   * A value of zero (`Duration.days(0)`) will not create RotationRules.
    *
    * @default Duration.days(30)
    */