chore(ci): remove old dependency check workflow

[erikburt]

This removes an old workflow that was always skipping. Related to #22070.

This workflow (https://github.com/smartcontractkit/chainlink/blob/develop/.github/workflows/dependency-check.yml) that is not doing anything and is superseded by the org-wide workflow.

1. The org-wide workflow is "Dependency Review - Vulnerability", and so this one shouldn't be needed
2. This workflow is currently doing nothing every time.
   • The first job has an output of: changes: ${{ steps.changes.outputs.src }}
   • The second job conditionally runs steps based on needs.changes.outputs.src == 'true' (invalid output, will never run)
   • If you fix the conditionals, it's actually just broken: https://github.com/smartcontractkit/chainlink/actions/runs/24589574843/job/71907264862

https://github.com/smartcontractkit/chainlink/actions/workflows/dependency-check.yml?query=is%3Afailure
All failures are actually unrelated to a dependency issue, and due to git/gh availability issues or other things. The only thing this workflow is doing is using github runners, and causing pr + merge queue failures when a git operation fails.

Note

I have already got the previously required check removed.

[github-actions]

✅ No conflicts with other open PRs targeting develop

[Copilot]

Pull request overview

Risk Rating: LOW

Removes a repository-local GitHub Actions workflow (dependency-check.yml) that was effectively non-functional (skipping due to incorrect outputs/conditions) and is superseded by an org-wide dependency review workflow. This should reduce spurious CI/merge-queue failures caused by unrelated runner/git issues in that workflow.

Changes:

• Deletes the deprecated .github/workflows/dependency-check.yml workflow.
• Eliminates a broken job-output/conditional chain that prevented the workflow’s vulnerability check steps from ever running.

Areas needing scrupulous human review:

• Confirm branch protection / merge queue required checks are updated to no longer require the deleted workflow’s check name(s), otherwise PRs could become blocked after merge.