(packaging) (#22726) Add saucy cow to defaults

Saucy is coming out soon, and we would like to be able to provide
packages for it in our builds. To do this, we need to add the saucy cow
to our cow defaults.
Merge pull request #155 from melissaanne/maint/stable/add-saucy

(packaging) (#22726) Add saucy cow to defaults