Fix dependency-review.yml for PR only

Author: garydgregory

.github/workflows/dependency-review.yml

@@ -29,6 +29,3 @@ jobs:
         uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: 'Dependency Review PR'
         uses: actions/dependency-review-action@4081bf99e2866ebe428fc0477b69eb4fcda7220a # v4.4.0
-        with:
-          base-ref: ${{ github.event.before }}
-          head-ref: ${{ github.sha }}