ci: add {base,head}-ref to dep review check (caddyserver#7064)

Signed-off-by: Mohammed Al Sahaf <msaa1990@gmail.com>

Author: mohammed90

.github/workflows/lint.yml

@@ -85,3 +85,6 @@ jobs:
         uses: actions/dependency-review-action@v4
         with:
           comment-summary-in-pr: on-failure
+          # https://github.com/actions/dependency-review-action/issues/430#issuecomment-1468975566
+          base-ref: ${{ github.event.pull_request.base.sha || 'master' }}
+          head-ref: ${{ github.event.pull_request.head.sha || github.ref }}