chore(ci): add a workflow for DCO check to avoid DCO bot system failu…

…re (#4825)

Signed-off-by: Ryohsuke Mitsudome <[email protected]>

.github/workflows/dco.yaml

@@ -0,0 +1,21 @@
+name: DCO
+# ref: https://github.com/anchore/syft/pull/2926/files
+on:
+  pull_request:
+jobs:
+  dco:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup Python 3.x
+        uses: actions/setup-python@v5
+        with:
+          python-version: 3.x
+
+      - name: Check DCO
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          pip3 install -U dco-check
+          dco-check --verbose --exclude-pattern 'pre-commit-ci\[bot\]@users\.noreply\.github\.com'