fix(ci): unblock fork PR autograder checkout

[lassebenni]

Summary

• Student fork PRs fail grade CI with: Refusing to check out fork pull request code from a pull_request_target workflow
• Root fix: HackYourFuture/github-actions#4
• This PR temporarily pins the reusable workflow to that fix so Week 12 PRs grade again

Follow-up

After HYF merges #4, revert this pin to HackYourFuture/github-actions/...@main.

Test plan

• Merge this PR
• Re-run grade on a student fork PR (e.g. Mohamad bader AA #3)
• Confirm checkout + score comment succeed

Made with Cursor

[github-actions]

📝 HackYourFuture auto grade

Assignment Score: 25 / 100 ❌

Status: ❌ Not passed
Minimum score to pass: 60
🧪 The auto grade is experimental and still being improved

Test Details

=== Week 12 Autograder — Orchestrated Pipeline ===
  ✓ PASS  found dags/taxi_pipeline.py
  ✓ PASS  found tests/test_dag_integrity.py
  ✓ PASS  found requirements.txt
  ✓ PASS  found RUNBOOK.md
  ✓ PASS  found ASSIGNMENT_REPORT.md
  ✓ PASS  found AI_ASSIST.md
  ✓ PASS  Level 1: required files (20/20 pts)
  ✗ FAIL  dags/taxi_pipeline.py: raise NotImplementedError still present — the DAG is not implemented
  ✓ PASS  dags/taxi_pipeline.py: defines a @dag with tasks
  ✓ PASS  Level 2: DAG implemented (5/15 pts)
  ✗ FAIL  dags/taxi_pipeline.py: only 1/3 expected tasks found (ingest, dbt_run, dbt_test)
  ✗ FAIL  dags/taxi_pipeline.py: no >> dependency chain found
  ✓ PASS  Level 3: sequential tasks (0/20 pts)
  ✗ FAIL  dags/taxi_pipeline.py: no uvx found — plain 'dbt' crashes on Python 3.14 (see Chapter 4)
  ✗ FAIL  dags/taxi_pipeline.py: no 'retries' found in default_args
  ✓ PASS  Level 4: uvx dbt + retries (0/20 pts)
  ✗ FAIL  dags/taxi_pipeline.py: no {{ ds }} / logical_date / get_current_context found — partition must come from the run date
  ✗ FAIL  dags/taxi_pipeline.py: catchup=False not found — required for safe normal operation
  ✓ PASS  Level 5: parameterized runs (0/15 pts)
  ✗ FAIL  RUNBOOK.md: still a template (374 chars, 6 TODO marker(s)) — fill in all four sections
  ✗ FAIL  AI_ASSIST.md: still a template (301 chars, 3 TODO marker(s))
  ✓ PASS  Level 6: documentation (0/10 pts)

Score: 25 / 100  (passing: 60)  pass=false

Reminder: the shared-Airflow deploy, the green run, and backfill
idempotency are Target-tier items a teacher reviews by hand — a high
static score here is necessary but not sufficient for Target.