FYI, many more TF PRs: internal pending changes show as PRs

[Austin Anderson]

Hi Deven (+SIG Build)

I wanted to let you know of a change that we made to TensorFlow's code review process this week. All of our pending internal changes get converted to PRs to the tensorflow/tensorflow repository, which is going to cause a lot more hits against your AMD ROCm community build CI.

For context for SIG Build: we're planning to migrate our blocking presubmits to GitHub-visible checks as part of cleaning up our presubmits. This should make the presubmit checks on GitHub more useful. We removed a bunch of the existing non-blocking presubmits while we're working on this.

If you want to ignore all of these pending-change PRs, you can ignore PRs submitted by "copybara-service@". Here is an example: https://github.com/tensorflow/tensorflow/pull/54553

Austin