how to uninstall pyenv(installed by homebrew) on Mac

From the docs:

Uninstalling pyenv

The simplicity of pyenv makes it easy to temporarily disable it, or
uninstall from the system.

1. To disable Pyenv managing your Python versions, simply remove the pyenv init line from your shell startup configuration. This will remove Pyenv shims directory from PATH, and future invocations like python will execute the system Python version, as before Pyenv.

   pyenv will still be accessible on the command line, but your
   Python apps won’t be affected by version switching.

2. To completely uninstall pyenv, perform step (1) and then remove its root directory. This will delete all Python versions that were installed under $(pyenv root)/versions/ directory:

   rm -rf $(pyenv root)
   

   If you’ve installed Pyenv using a package manager, as a final step perform the Pyenv package removal. For instance, for Homebrew:

    brew uninstall pyenv