fix: use PR head ref for Scalafmt Check checkout to support forks and deleted branches

[Copilot]

Overview

The "Scalafmt Check" workflow was using ref: ${{ github.event.pull_request.head.ref }} (branch name) for checkout. This fails when the branch no longer exists on the remote, and also breaks for fork PRs where the branch lives on the contributor's fork rather than the upstream repo.

Fix: Replace with refs/pull/${{ github.event.pull_request.number }}/head — a GitHub-managed ref that exists for every PR regardless of origin (fork or same-repo) and survives branch deletion.

# Before — fails if branch deleted or PR is from a fork
ref: ${{ github.event.pull_request.head.ref }}

# After — always resolves to the PR head commit
ref: refs/pull/${{ github.event.pull_request.number }}/head

Release Notes

• Fixed "Scalafmt Check" CI job failing on PRs from forks or with deleted head branches

[dk1844]

LGTM, let's try it.

[github-actions]

JaCoCo code coverage report - scala 2.12.20

Metric (instruction)	Coverage	Threshold	Status
Overall	83.2%	80.0%	✅
Changed Files	0.0%	80.0%	✅

Report	Coverage (O/Ch)	Threshold (O/Ch)	Status (O/Ch)
spark-data-standardization Jacoco Report - scala:2.12.20	83.2% / 0.0%	80.0% / 80.0%	✅/✅

File Path	Coverage	Threshold	Status

No changed file in reports.

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Run 30548305163 · Event: pull_request

[MatloaItumeleng]

LGTM