13.0.0-rc1 pushed out to Monday

Project Infrastructure Release Testers
#1

Hi,

I'm going to give the release/13.x branch a few more days to
stabilize, so I plan on tagging 13.0.0-rc1 on Monday now
instead of Friday.

-Tom

#2

I must've missed the announcement of the branch split. I suppose this
is my final cue to start testing.