title: pathlib joinpath in pandas 3.7
body: <p>I am trying to join a relative path to an absolute one. I am confused as to this behavior:</p>
  
  <pre><code>from pathlib import Path
  path = Path("/an/absolute/path/test")
  path.joinpath("/../relative/path", "some_suffixes")
  </code></pre>
  
  <p>gives</p>
  
  <pre><code>PosixPath('/../relative/path/some_suffixes')
  </code></pre>
  
  <p>Why does this drop the first part of the path? What I expect is</p>
  
  <pre><code>PosixPath('/an/absolute/path/test/../relative/path/some_suffixes')
  </code></pre>