Release/20.2.1

[pradyunsg]

This is the result of:

git checkout 20.2
git checkout -b release/20.2.1

git cherry-pick -m 1 686c11a7a
git cherry-pick -m 1 d8ba146e6
git cherry-pick -m 1 e7357c71c
git cherry-pick -m 1 70768de0a
git cherry-pick -m 1 0c48ec069
git cherry-pick -m 1 e35135b92
git cherry-pick -m 1 4fa31d509
git cherry-pick -m 1 7e6ff08aa
git cherry-pick -m 1 e51a02796
git cherry-pick -m 1 9add5aa92
git cherry-pick -m 1 930aa5c70
git cherry-pick -m 1 31299ee37

nox -s prepare-release -- 20.2.1

I have a feeling we'd need to cleanup the NEWS fragments for the already-merged PRs after this release.

[pradyunsg]

taps feet, waiting on the CI