How to add pip in the venv for Python 3.12

[bebound]

Output of brew config

No

Output of brew doctor

No

Description of issue

After Homebrew/brew#16306, without_pip=false is removed. Python 3.12 does not install pip in virtual env.
Our formula needs pip. What's the recommended way to add pip into venv?

[branchvincent]

If pip is needed at runtime (note of course this is very rare), then it can and should be declared as a normal dependency, so in pyproject.toml's project.dependencies or setup.py's install_requires