Revert: Undo Blacksmith migration from PR #559

[pyramation]

Summary

This PR reverts the Blacksmith runner migration introduced in PR #559. The changes restore the original GitHub Actions configuration:

• Reverts runs-on from Blacksmith runners (blacksmith-4vcpu-ubuntu-2404, blacksmith-4vcpu-ubuntu-2404-arm) back to GitHub-hosted runners (ubuntu-latest, ubuntu-24.04-arm)
• Reverts Docker setup from useblacksmith/setup-docker-builder@v1 back to docker/setup-buildx-action@v3
• Reverts build actions from useblacksmith/build-push-action@v2 back to docker/build-push-action@v5/v6
• Restores GHA cache configuration (cache-from: type=gha, cache-to: type=gha,mode=max)

Additional changes (per user request):

• Removes container: pyramation/node-sqitch:20.12.0 from the test workflow
• Updates service hostnames from Docker network names to localhost (PGHOST, MINIO_ENDPOINT, TEST_DATABASE_URL)
• Adds explicit actions/setup-node@v4 step with Node.js 20

Files changed: docker-launchql.yaml, docker.yaml, run-tests.yaml

Review & Testing Checklist for Human

• Verify CI tests pass - Removing the node-sqitch container is a significant change; tests now run directly on the runner and may be missing dependencies (e.g., sqitch CLI if any tests require it)
• Confirm all service connections work with localhost instead of Docker network hostnames
• Verify Docker builds complete successfully (may need to trigger a manual workflow run or wait for a merge to main)

Notes

Requested by: Dan Lynch (@pyramation)
Link to Devin run: https://app.devin.ai/sessions/54faae16c78b4b8e9d5f3a96b2ce062b

[devin-ai-integration]

🤖 Devin AI Engineer

I'll be helping with this pull request! Here's what you should know:

✅ I will automatically:

• Address comments on this PR. Add '(aside)' to your comment to have me ignore it.
• Look at CI failures and help fix them

Note: I can only respond to comments from users who have write access to this repository.

⚙️ Control Options:

• Disable automatic comment and CI monitoring