Revert "Temporarily skip DCO check"

re-enable the DCO check, which was temporarily disabled to migrate
old commits from github.com/docker/libkv

This reverts commit 7d7225fae657a18f8f384273a2313a288d84a021.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

.github/workflows/.dco.yml

@@ -35,14 +35,14 @@ jobs:
               return context.payload.pull_request.base.ref;
             }
             return context.ref.replace(/^refs\/heads\//g, '');
-#      -
-#        name: Validate
-#        run: |
-#          docker run --rm \
-#            -v "$(pwd):/workspace" \
-#            -e VALIDATE_REPO \
-#            -e VALIDATE_BRANCH \
-#            alpine:${{ env.ALPINE_VERSION }} sh -c 'apk add --no-cache -q bash git openssh-client && git config --system --add safe.directory /workspace && cd /workspace && hack/validate/dco'
-#        env:
-#          VALIDATE_REPO: ${{ github.server_url }}/${{ github.repository }}.git
-#          VALIDATE_BRANCH: ${{ steps.base-ref.outputs.result }}
+      -
+        name: Validate
+        run: |
+          docker run --rm \
+            -v "$(pwd):/workspace" \
+            -e VALIDATE_REPO \
+            -e VALIDATE_BRANCH \
+            alpine:${{ env.ALPINE_VERSION }} sh -c 'apk add --no-cache -q bash git openssh-client && git config --system --add safe.directory /workspace && cd /workspace && hack/validate/dco'
+        env:
+          VALIDATE_REPO: ${{ github.server_url }}/${{ github.repository }}.git
+          VALIDATE_BRANCH: ${{ steps.base-ref.outputs.result }}