I cannot open terminal in Ubuntu after updating to python3.13

[KhardanOne]

I followed this tutorial on a virtual Ubuntu box to update the python3, except I used python3.13:
https://cloudbytes.dev/snippets/upgrade-python-to-latest-version-on-ubuntu-linux

Everything seemed to work nicely until I restarted the VM. But since then I cannot open the terminal window or the Settings window. So I cannot check which Ubuntu version is that. It is an LTS, probably Fossa, maybe newer.

I went to terminal with CTRL-ALT-F5, and checked some things that might be of use:

Any ideas how to fix it?
(I'm not a Linux expert, but most probably you've already figured that out.)