title: pipenv under pyenv fails to upgrade its instance under pyenv
body: <p>After brew upgrading pipenv in MacOS</p>
  <pre><code>==&gt; Installing pipenv
  ==&gt; Pouring pipenv--2022.1.8.big_sur.bottle.tar.gz
    /usr/local/Cellar/pipenv/2022.1.8: 1,767 files, 28MB
  </code></pre>
  <p>I see that the version of <code>pipenv</code> under <code>pyenv</code> is NOT updated:</p>
  <pre><code>&gt; which pipenv
  pipenv is /Users/me/.pyenv/shims/pipenv
  pipenv is /usr/local/bin/pipenv
  </code></pre>
  <p>UPDATED:</p>
  <pre><code>&gt; /usr/local/bin/pipenv --version
  pipenv, version 2022.1.8
  </code></pre>
  <p>NOT UPDATED:</p>
  <pre><code>&gt; /Users/me/.pyenv/shims/pipenv --version
  pipenv, version 2020.11.15
  </code></pre>
  <p>How do I make sure the version under <code>pyenv</code> gets upgraded also?</p>