Set expiration date in the `timeout-handler` instead of an sleep

[tty47]

update this command: https://github.com/celestiaorg/knuu/blob/2c3edce891086d293686a50a12d042dc41922283/pkg/knuu/knuu.go#L229

to an expiration date

[mojtaba-esk]

if the handler at some point restarts, the timeout also resets so it is more reliable to have a fixed date/time.

[tty47]

do we still need this one?