[ENH] Automerge passing dependabot PRs

[charlesbluca]

Is your feature request related to a problem? Please describe. Currently, the automated version bumps done by Dependabot can get quite noisy since they require manual review and merging.

Describe the solution you'd like It would be nice if we added some form of automerging CI that merged in Dependabot PRs once all CI checks on the PR passed; to be on the safe side, we would probably also want to make sure some of the workflows that are currently only running on pushes to main or a schedule (Docker, pip builds, gpuCI updates, etc.) also run on these PRs.

Describe alternatives you've considered We could reduce day-to-day noisiness by changing the frequency Dependabot runs on, but that doesn't save us the time of needing to manually merge the PRs.