Failure to process unstable interface through `include`

[alexcrichton]

This input:

package a:b1;

world the-world {
  include a:b2/the-world;
}

package a:b2 {
  world the-world {
    @unstable(feature = disabled)
    import a:b3/thing;
  }
}

package a:b3 {
  @unstable(feature = disabled)
  interface thing {}
}

passed through wasm-tools component wit generates:

error: interface not found in package
     --> foo.wit:10:17
      |
   10 |     import a:b3/thing;
      |                 ^----