title: Cannot install Python 3.7 on osx-arm64
body: <p>I am trying to create a new environment with Python 3.7 using Conda like:</p>
  <pre class="lang-bash prettyprint-override"><code>conda create -n qnn python=3.7 
  </code></pre>
  <p>I got following errors:</p>
  <pre class="lang-bash prettyprint-override"><code>Collecting package metadata (current_repodata.json): done
  Solving environment: failed with repodata from current_repodata.json, will retry with next repodata source.
  Collecting package metadata (repodata.json): done
  Solving environment: failed
  
  PackagesNotFoundError: The following packages are not available from current channels:
  
    - python==3.7
  
  Current channels:
  
    - https://conda.anaconda.org/conda-forge/osx-arm64
    - https://conda.anaconda.org/conda-forge/noarch
  
  To search for alternate channels that may provide the conda package you're
  looking for, navigate to
  
      https://anaconda.org
  
  and use the search bar at the top of the page.
  </code></pre>
  <p><strong>Why is Python 3.7 apparently unavailable?</strong></p>
  <hr />
  <h2>System Details</h2>
  <p>This is on an Apple Silicon (<strong>osx-arm64</strong>) machine running macOS.</p>