I had a similar issue, and ended up doing a git clone.
St7789, Python, Legacy OS, can’t get it to work? - Support - Pimoroni Buccaneers
git clone https://github.com/pimoroni/st7789-python
cd st7789-python
./install.sh
Having a look see, I don’t think thats an option for you?
You’ll likely have to setup a virtual enviromnt and install into that, via the manual methode?
@hel may be able to help?