pyenv-doctor fails to check for patch command

[jbirch-atlassian]

Unsure if this lands in the "pyenv needs this" bucket or "this specific Python version build needs this" bucket, but it strikes me that pyenv-doctor should be aware that other pyenv plugins will need this to be able to install Python versions.

It is possible to have a system which looks perfectly cromulent to pyenv doctor, but fails to build Python versions based on missing the command patch.

➜  git:(master) pyenv doctor
Cloning /var/home/jbirch/.pyenv/plugins/pyenv-doctor/bin/.....
Installing python-pyenv-doctor...
Installed python-pyenv-doctor to /tmp/pyenv-doctor.20220128161440.90623/prefix

Congratulations! You are ready to build pythons!

➜  git:(master) pyenv install 3.7.12                          
Downloading Python-3.7.12.tar.xz...
-> https://www.python.org/ftp/python/3.7.12/Python-3.7.12.tar.xz
Installing Python-3.7.12...
/var/home/jbirch/.pyenv/plugins/python-build/bin/python-build: line 1638: patch: command not found