workflows/pr-receive: Ignore pull requests with 10 or more commits (#66320)

This will cause the auto-labeler not to run on pull requests with more
than 10 commits. Usually larger pull requests like this are mistakes and
we want to avoid generating an excessive amount of notifications.

It may be possible for legitimate pull requests to have 10 or more
commits from people pushing fixup commits to addresss review comments.
However, these pull requests should already have the correct labels by
the time they grow to 10 commits.