Huh. stubtest passed locally but failed here. Do you have to clear something out to get a proper check?

Edit: maybe it was because I had not committed the change before the local check.

Owee, I'm MrMeeseeks, Look at me.

There seem to be a conflict, please backport manually. Here are approximate instructions:
They assume that the base project is the Git remote upstream and your fork is origin.

1. Update backport branch.

git fetch upstream v3.11.x:v3.11.x
# or `git pull upstream v3.11.x` if you are on v3.11.x

2. Create PR branch.

git switch -c auto-backport-of-pr-32344-on-v3.11.x v3.11.x

3. Cherry pick the first parent branch of this PR on top of the older branch:

git cherry-pick -x -m1 a99bc61d82b76eab80509a57e39fa20a556d1985

4. You will likely have some merge/cherry-pick conflict here, fix them and commit:

git commit -am 'Backport PR #32344: TYP: PieContainer does not inherit from Container'

5. Push to a named branch:

git push --set-upstream origin auto-backport-of-pr-32344-on-v3.11.x

6. Create a PR against branch v3.11.x, I would have named this PR:

Backport PR #32344 on branch v3.11.x (TYP: PieContainer does not inherit from Container)

And apply the correct labels and milestones.

Congratulations — you did some good work! Hopefully your backport PR will be tested by the continuous integration and merged soon!

Remember to remove the Still Needs Manual Backport label once the PR gets merged.

If these instructions are inaccurate, feel free to suggest an improvement.