Add renovate workflows triggers

[fleet-updates-culture-amp-sre]

Purpose

What is this PR about?

We are improving our workflows for running Renovate at Culture Amp. The 3 workflows we are adding to your repo are triggers to run renovate workflows. We are adding these to all repos using Renovate.

Action required

These workflows are well tested and do not affect production code or deployment. They are safe to merge as-is.

• Merge the PR with 3 new workflows with specific triggers

Context

RFC: https://cultureamp.atlassian.net/wiki/spaces/DE/pages/4241260845/RFC+tweaks+to+Renovate+runs+to+allow+manual+triggers+merge+queues+and+less+effort
Jira: https://cultureamp.atlassian.net/browse/FEF-1641

Here is summary of features:

• React to checkboxes being ticked in PRs and the dependency dashboard
  • Retrying/rebasing/fixing conflicts in updates
• Automatically try to merge updates instead of waiting for renovate to merge one per run
  • This is triggered by push to the renovate/rollup branch
  • This allow much more frequent and efficient auto merges
  • It also means a single Renovate run can open many PRs and then this process automerges them, rather than running Renovate ~24 times per weekend with just a few updates each time