title: neovim lsp diagnostic get_count deprecated but unused
body: <p>I'm using nvim v0.7.0-dev, Ubuntu 20.04 LTS.
  And I see the following error:</p>
  <pre><code>vim.lsp.diagnostic.get_count is deprecated. See :h deprecated
  </code></pre>
  <p>But I'm not using 'get_count', so, I can't change it, or remove or whatever. Why I see this error? and how can I solve it?</p>