Lr does not need to be "deactivatde". If you no longer want to use it on a particular machine, just uninstall it.
I want to move mine to new laptop. Is that possible?
All you need to activate is your LR serial number.
The license agreements allows for two installs present Mac & or Win with one in use at any point in time.
One owner / user.
You can install / uninstall as often as necessary once you respect the license agreement, single user, one application in use at any point in time.
I have no objection to what DdeGannes said, but in case still not clear:
Some software requires deactivation before it can be activated again somewhere else - Lightroom is NOT such a software.
* Software + serial-number is all you need to run, de-installation to respect license agreement is based on the honor system, although there could be detection/protection mechanisms in place in case of abuse - dunno..