Add dco_merge_group workflow

Signed-off-by: Yuri Shkuro <[email protected]>

Author: yurishkuro

.github/workflows/dco_merge_group.yml

@@ -0,0 +1,14 @@
+# Fake "DCO check" workflow inspired by https://github.com/onnx/onnx/pull/5398/files.
+# The regular DCO check is required, but it does not run from a merge queue and there is
+# no way to configure it to run.
+name: DCO
+on:
+  merge_group:
+
+permissions:  
+  contents: read
+jobs:
+  DCO:
+    runs-on: ubuntu-latest
+    steps:
+      - run: echo "Fake DCO check to avoid blocking the merge queue"