[ANNOUNCE] Release 1.13 branch

[dwysakowicz]

Hi committers!

I'd like to remind that we agreed we won't cut off the 1.13 branch until
we are a bit more confident with the stability of the master branch.
Therefore I'd kindly ask not to push the release-1.13 branch yet.

I did push that branch accidentally when creating the rc0, but I
reported that to the ASF infra and removed the branch in the morning.
Unfortunately the branch has been pushed again since then ;). That's why
I am writing this email. I'll remove the branch again and we will most
probably perform a proper cut early next week.

Does anyone have a different opinion? Would anyone benefit from cutting
off the branch already? If so, please let me know.

Best,

Dawid