Add DCO check using GHA (#520)

Signed-off-by: Marcin Owsiany <[email protected]>

Author: porridge

.github/workflows/dco.yaml

@@ -0,0 +1,17 @@
+name: DCO
+on: [pull_request]
+
+jobs:
+  commits_check_job:
+    runs-on: ubuntu-latest
+    name: DCO check
+    steps:
+    - name: Get PR Commits
+      id: 'get-pr-commits'
+      uses: tim-actions/[email protected]
+      with:
+        token: ${{ secrets.GITHUB_TOKEN }}
+    - name: DCO Check
+      uses: tim-actions/[email protected]
+      with:
+        commits: ${{ steps.get-pr-commits.outputs.commits }}