publish for Scala 2.13.0-RC1

[SethTisue]

need for cats to publish, I believe

[rossabaker]

I think https://github.com/typelevel/sbt-catalysts/pull/98 is necessary, but am not confident it's sufficient.

[SethTisue]

cats dropped its catalysts dependency

paiges still uses it a little, but only in test code

algebra still uses it a little in both main and test code

I'm not sure where else the dependency might be lurking

[SethTisue]

should this still be open?