i've run into the same issue on Ubuntu 20.04, the problem is python3.8 is too old for bootstrapping this project.

try to install python3.11 at least:

sudo apt install python3.11 python3.11-dev python3.11-venv

create a virtual environment:

python3 -m venv venv
source .venv/bin/activate

and try to run bootstrap script from there.

P.S. do not update system Python on Ubuntu (leave it 3.8), otherwise it might cause problems in OS housekeeping