title: Immutable (uncontainerized) elements in arrays created by deepmap
body: <p>If I understand the Raku docs correctly, the elements of Arrays are always containerized, i.e. Scalars. However, the deepmap method seems to create (inner) Arrays with uncontainerized elements:</p>
  <pre><code>my @a = [1, [2, 3]];
  my @b = @a.deepmap: *.clone;
  say @b[0].VAR.^name;     # Scalar, this is OK
  say @b[1].^name;         # Array, as expected
  say @b[1][0].VAR.^name;  # Int, why?
  @b[0] = 4;               # this works
  @b[1][0] = 5;            # error: Cannot assign to an immutable value
  </code></pre>
  <p>Why does this happen?</p>
  <p>For context, I originally wanted to use <code>.deepmap: *.clone</code> to create a deep copy, but I needed the copy to be mutable. I solved the problem by using <code>@a.deepmap: { my $ = .clone }</code>, but I am still curious why this happens.</p>