How can I de-license an installed copy if the computer doesn't exist any longer?

12 years ago I bought a retail copy of Photoshop CS6.

Installed it, licensed it online, used it. No problems.

Since then I had several computers. I remember that I had to de-license my copy once or twice to install it on a laptop or on a new computer. It always worked like a charm.

Now my recent PC broke and I got a new one. The old one is physically broken and we already sent it to recycling centre.

When trying to install Photoshop on my new computer, I get an error message that the number of my licenses is exceeded and that I need to de-license.

I cannot do that, because the old computer doesn't exist any longer.

I contacted the support team via chat. The chat support told me this is a problem they cannot solve and they will forward my problem to a special licensing support team.

The special licensing support team just send me an automated mail me with a link to this page

https://helpx.adobe.com/de/x-productkb/policy-pricing/error-activation-limit-reached-sign.html

It basically says "If you cannot de-license your software because you already uninstalled it, just install it again on the old computer and de-license it."

In the same e-mail they stated that my support case is now closed.

So I'm back to step 1.

How can I de-license an installed copy if the computer doesn't exist any longer?