Cherry-pick of #42061 to preview
----
Don't crash in generate-release-notes on the first stable
commit on a branch.
Release Notes:
- N/A
Co-authored-by: Conrad Irwin <conrad.irwin@gmail.com>
It turns out that messing with the git repo created by the github action
is
tricky, so we'll just clone our own.
On my machine, a shallow tree-less clone takes <500ms
Release Notes:
- N/A
While I don't expect these to be useful for our weekly minor releases, I
hope that this will save a step for people doing mid-week patches.
Release Notes:
- N/A
