chore: add action to trigger renovate
Created by: bobheadxi
for https://github.com/sourcegraph/sourcegraph/issues/13122
This change adds an action that runs when the buildkite check suite completes successfully on sourcegraph/sourcegraph@main
to trigger a renovate run immediately on deploy-sourcegraph
(https://github.com/sourcegraph/deploy-sourcegraph/pull/845) to avoid the latency of having renovate detect new images itself (at least hopefully, unless I've completely misunderstood the github action)