always use dev branch of openproject-flavours

even if it had other branches, the git ref used here is the core ref to be built not the flavours ref to be used

.github/workflows/continuous-delivery.yml

@@ -24,4 +24,4 @@ jobs:
           curl -i --fail-with-body -H"authorization: Bearer $TOKEN" \
             -XPOST -H"Accept: application/vnd.github.v3+json" \
             https://api.github.com/repos/$REPOSITORY/actions/workflows/$WORKFLOW_ID/dispatches \
-            -d '{"ref": "${{ github.ref_name }}", "inputs": { "ref" : "'$CORE_REF'" }}'
+            -d '{"ref": "dev", "inputs": { "ref" : "'$CORE_REF'" }}'