Welcome to the Magix Sound Forge users community @CJ-Brown
You do not have to deactivate SF-11 on the old PC. SCS (Sony) versions of Sound Forge were not limited to only two (2) PCs, as is the case with (Magix) Sound Forge 12 and later. Download the latest Sound Forge 11 build from Magix Service Center> My Products' or Magix Download Center and install. When you initially launch SF-11, the online activation procedure should appear which asks for your activation serial code.. I am not sure if SF-11 needs your SCS user name (email address) as well.
Do you have the installer for SF11? If so, run it on your new computer, assuming that it will install properly under Win 11. After all, it is now a rather "old" version you are trying to install on a "new" operating system.
If you do not have the installer you will need to access your Magix account, log in, go to My products and find the listing for SF11. Download the installer and run it.
One other thing to remember: you cannot literally "move" (i.e., transfer) an app from one computer to another; you must install it on the new one.