Update codecov.yml

Author: icfaust

.github/workflows/codecov.yml

@@ -46,7 +46,7 @@ jobs:
          chmod +x codecov
      - name: Upload to codecov
        run: |
-         echo $GITHUB_REF
+         echo ${{ github.event.workflow_run.head_branch }}
          export PR=${{ github.event.workflow_run.pull_requests[0].number }}
          export SHA=${{ github.event.workflow_run.head_sha }}
          export VARARGS="-n github"