coyoneda-0.5.2 beta regression

[est31]

coyoneda version 0.5.2 regressed from stable to beta (full log):

error: type `morphism::Void` is private
   --> src/lib.rs:142:35
    |
142 |         Coyoneda{point: x, morph: Morphism::new()}
    |                                   ^^^^^^^^^^^^^
                        ^ 

cc @srijs

[petrochenkov]

This is a known regression as well (see #42125 (comment)).
The issue was actually in morphism, not coyoneda, and I sent a PR to fix it in May, but it was ignored.

[nikomatsakis]

Closing since there is a pending PR to fix, and no particular further action for us to take at this time.