title: Sorbet asking a `sig` for `attr_reader`
body: <p>Sorbet is showing an error for the attr_reader, but correct me if I am wrong, sigs are required when the function is declared, not called, right?</p>
  
  <p>I have tried going through the documentation but all I got is this note</p>
  
  <p>Note: Many Ruby constructs that look like local variables are actually method calls without parens! Specifically, watch out for attr_reader and zero-argument method definitions.</p>
  
  <pre><code>app/util/hodor.rb:125: This function does not have a `sig` https://sorbet.org/docs/error-reference#7017
       125 |  attr_reader(:collection_name)
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  </code></pre>