Add support for GitHub Merge Queues

[mars-lan]

When using GitHub Merge Queue to merge a PR, the event name will be merge_group rather than pull_request.

[orgoro]

@mars-lan thanks!
can you help verify that the event properties contain -

const {pull_request} = context.payload
const base = pull_request?.base.sha
const head = pull_request?.head.sha

base/head sha?
if you can send a link to the object in the docs

[techman83]

There doesn't appear to be pull request details available in a merge group payload -> https://docs.github.com/en/webhooks/webhook-events-and-payloads#merge_group

[orgoro]

We need a way to compare two different commits

If you want to add support to that in the code I will merge it

[tylertitsworth]

github.event.merge_group.base_sha == github.event.pull_request.base.sha
github.event.merge_group.head_sha == github.event.pull_request.head.sha