Overview
This is a memorandum on how to trigger GitHub Actions from Drupal events.
The following site was helpful:
https://qiita.com/hmaruyama/items/3d47efde4720d357a39e
Pipedream Configuration
Create a workflow that includes a trigger and a custom_request.
For the trigger, please refer to the following:
https://qiita.com/hmaruyama/items/3d47efde4720d357a39e#pipedream側の設定
In custom_request, configure the dispatch settings.
https://docs.github.com/ja/rest/repos/repos?apiVersion=2022-11-28#create-a-repository-dispatch-event
Configure the settings as follows:
curl -L \
-X POST \
-H "Accept: application/vnd.github+json" \
-H "Authorization: Bearer <YOUR-TOKEN>" \
-H "X-GitHub-Api-Version: 2022-11-28" \
https://api.github.com/repos/OWNER/REPO/dispatches \
-d '{"event_type":"webhook"}'


Drupal Configuration
Install the following module:
https://www.drupal.org/project/webhooks
After installation, configure it on the following page:
/admin/config/services/webhook

GitHub Actions Configuration
Configure repository_dispatch as follows. This allows GitHub Actions to be executed based on requests from Pipedream.
name: Build and Deploy to Production
on:
push:
branches:
- main
# Allows external webhook trigger
repository_dispatch:
types:
- webhook
permissions:
contents: read
concurrency:
group: "build-and-deploy"
cancel-in-progress: true
jobs:
...
Summary
It may also be possible to send notifications to GitHub by creating a custom Drupal module without using Pipedream. (Such a module has likely already been developed, but I was unable to find one.)
I hope this serves as a useful reference.