So you can unyank a gem with gem yank --undo...I
would suggest just to bump by a patch version, perhaps 0.9.91 or
0.9.9.1. You're not going to run out of gem versions any time soon,
and unless that gem has malicious or harmful code in it it's
probably not worth it to perma-delete.
Ah, so this is expected. When you yank the last version your
ownership is revoked so anyone can take over the namespace. I see
you've pushed a new version so you should have control back over
it, so you can undo the yank now.