title: "[lib] requires [dep], which is not installed" when running PR tests on conda-forge feedstock, despite explicit call in grayskull-generated meta.yaml
body: <p>I'm trying to upgrade the conda-forge version of <code>xagg</code> to the latest version (v0.3.0). The built-in Azure Pipelines tests that run when I set up a PR of the feedstock into the conda-forge repository however fail, with the error:</p>
  <pre><code>import: 'xagg'
  import: 'xagg'
  + pip check
  xagg 0.3.0 requires pytables, which is not installed.
  </code></pre>
  <p>(the full log is <a href="https://dev.azure.com/conda-forge/feedstock-builds/_build/results?buildId=486001&amp;view=logs&amp;j=656edd35-690f-5c53-9ba3-09c10d0bea97&amp;t=e5c8ab1d-8ff9-5cae-b332-e15ae582ed2d" rel="nofollow noreferrer">here</a>)</p>
  <p>The odd thing is that <code>pytables</code> is explicitly mentioned in the <code>meta.yaml</code> (which was generated through <code>grayskull</code> and is listed in the PR changes <a href="https://github.com/conda-forge/xagg-feedstock/pull/11/files#diff-f3725a55bf339595bf865fec73bda8ac99f283b0810c205442021f29c06eea9a" rel="nofollow noreferrer">here</a>), and, at least according to the test log, was correctly installed into the test docker environment:</p>
  <pre><code>The following NEW packages will be INSTALLED:
  
  [snip]
  
  pytables:                  3.7.0-py310hf5df6ce_0             conda-forge
  
  [snip]
  
  DEBUG:urllib3.connectionpool:https://conda.anaconda.org:443 &quot;GET /conda-forge/linux-64/pytables-3.7.0-py310hf5df6ce_0.tar.bz2 HTTP/1.1&quot; 200 4914957
  
  [snip]
  
  Preparing transaction: ...working... done
  Verifying transaction: ...working... done
  Executing transaction: ...working... done
  
  </code></pre>
  <p>Does anyone have any advice on how to troubleshoot this? The <a href="https://github.com/conda-forge/tqdm-feedstock/issues/104" rel="nofollow noreferrer">suggestions</a> I've seen so far are to explicitly list the dependency in the <code>meta.yaml</code>, which I have.</p>
  <p>I believe this may be a similar issue to <a href="https://stackoverflow.com/questions/67339524/publish-packages-in-conda-forge-receive-error-my-package-requires-pathlib-whic">this question</a>, though for an optional package, not a built-in one.</p>
  <p>Grateful for any help!</p>