This is highly unusual. Without a valid user account, no one can use Content Translation. A quick search reveals that the user account for ParovT exists but the user, and talk pages do not exist and there has been no contributions either. We do have plans to extend notifications such that users with long pending unfinished translations can be informed.

Well, this user does exist: https://en.wikipedia.org/w/index.php?title=Special%3ALog&type=&user=&page=User%3AParovT&year=&month=-1&tagfilter=

But he didn't make any other contributions.

@santhosh , is there anything that can be done in such a case when the locking user cannot be contacted?

We have a proposal for not blocking users: T86151: Allow different users to translate the same topic independently
Basically we can provide an option to continue the existing work or create their own version of the translation from scratch.

I think it is better to focus at the core problem than polish the coordination aspects since we can do little with those cases where the user really becomes inactive blocking a page from being translated. Nevertheless, we have also a proposal to remind users about old drafts that could help: T89707: Encourage users to publish old inactive unpublished translations (we can consider triggering that notification once a potential blocker is detected)