When I run poetry commands, I get the message:
Skipping virtualenv creation, as specified in config file.
I don't remember setting such a thing, and I don't really see anything relevant in the pyproject.toml. What config file is poetry talking about?
You can see current settings via poetry config --list. These settings are usually global settings. But it's also possible to have local settings due to a poetry.toml in the same folder as the pyproject.toml. Local configs can be set by a poetry config --local <configsetting>.
This is also described in the docs: https://python-poetry.org/docs/configuration/
A poetry config virtualenvs.create true is what you are looking for. This setting is the default value. So there is a good chance that you've changed it at some point.