How to build a Python project for a specific version of Python

Question

I have an app that I would like to deploy to AWS Lambda and for this reason it has to have Python 3.9.

I have the following in the pyproject.toml:

name = "app"
readme = "README.md"
requires-python = "<=3.9"
version = "0.5.4"

If I try to pip install all the dependencies I get the following error:

ERROR: Package 'app' requires a different Python: 3.11.1 not in '<=3.9'

Is there a way to specify the Python version for this module?

I see there is a lot of confusion about this. I simply want to specify 3.9 "globally" for my build. So when I build the layer for the lambda with the following command it runs:

pip install . -t pyhon/

Right now it has only Python 3.11 packaged. For example:

❯ ls -larth python/ | grep sip
siphash24.cpython-311-darwin.so

When I try to use the layer created this way it fails to load the required library.