Add GitHub action to create PRs merging google -> main (#2482)
Add GitHub action to create PRs merging google -> main (#2482)

This should provide a base point for periodic integrates.

Tested: no
google/iree,google/iree,google/iree,google/iree,iree-org/iree,iree-org/iree,iree-org/iree,google/iree,google/iree,google/iree,iree-org/iree,iree-org/iree,iree-org/iree,iree-org/iree