## Changes
Migrate workflows to Databricks-hosted GitHub Actions runners.
The GitHub-hosted runners can no longer be used because of security
hardening.
## Changes
The existing workflow already had 2 trigger conditions, so instead of
adding a third (and seeing more "skipped" jobs), I split them up into
dedicated workflow files, each with their own trigger condition.
The integration test status is reported back via commit status.
## Tests
We can confirm that everything works as expected as this PR moves from
here to the merge group to main.