Auto-deploy website after data processing completes

[Copilot]

Problem

The data processing workflow runs nightly to update contributor data, curated resources, Google Analytics statistics, and other dynamic content. However, these updates were not being deployed to the live website until the next code change was pushed to master. This created a delay between data updates and their visibility on the site.

Solution

This PR implements automatic deployment after the data processing workflow completes by:

1. Adding a repository_dispatch trigger to the deploy workflow that listens for data-update events
2. Adding a deployment trigger step at the end of the data processing workflow that dispatches the deploy workflow via GitHub API
3. Updating the production deployment condition to properly handle repository_dispatch events

How It Works

Data Processing (nightly) → Process Data → Upload Artifacts → Trigger Deploy
                                                                      ↓
                                            Deploy Workflow ← repository_dispatch
                                                                      ↓
                                            Build Site with Latest Data
                                                                      ↓
                                            Deploy to Staging & Production

When the data processing workflow runs (either on schedule or manually):

• Data is processed and uploaded as artifacts
• The deploy workflow is triggered via repository_dispatch event
• The deploy workflow downloads the latest data artifacts and builds the site
• Changes are deployed to both staging and production environments

Changes

.github/workflows/deploy.yaml

• Added repository_dispatch trigger with event type data-update
• Updated production deployment condition to include repository_dispatch events with proper logic:
  • push/workflow_dispatch: requires master branch
  • repository_dispatch: always allowed (runs on default branch automatically)
• Updated documentation comments

.github/workflows/data-processing.yml

• Added "Trigger deployment" step after artifact upload
• Uses GitHub API to dispatch the deploy workflow
• Only triggers on non-PR events (scheduled runs and manual dispatch)
• Uses existing GITHUB_TOKEN secret

Benefits

• ✅ Data updates are now deployed automatically without manual intervention
• ✅ No waiting for the next code change to publish data updates
• ✅ Maintains backward compatibility with existing triggers
• ✅ Follows GitHub Actions best practices
• ✅ No new secrets or credentials required

Fixes #456

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Auto-deploy after data update</issue_title>
<issue_description>@richarddushime currently, the data processing script runs nightly to update our data (e.g. contributors) - but that does not get deployed until the next change happens on the website. Can deploy be triggered at the end of that script? Or can we make sure in some other way that data updates filter through?</issue_description>

Comments on the Issue (you are @copilot in this section)

Fixes #456

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[github-actions]

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[LukasWallrich]

✅ This PR has been deployed to staging as part of an aggregated deployment. View at: https://staging.forrt.org

[LukasWallrich]

✅ This PR has been deployed to staging as part of an aggregated deployment. View at: https://staging.forrt.org

[richarddushime]

LGTM