do not care about merge_commit

scripts/commit-json.sh

@@ -12,10 +12,6 @@ author_name=$(git log -1 --pretty=format:'%an' $GITHUB_SHA)
 committer_email=$(git log -1 --pretty=format:'%ce' $GITHUB_SHA)
 committer_name=$(git log -1 --pretty=format:'%cn' $GITHUB_SHA)
 
-merge_commit_id=$(git rev-parse HEAD)
-merge_commit_title=$(git log -1 --pretty=%B | head -n 1)
-merge_commit_timestamp=$(git log -1 --format=%cd --date=iso-strict)
-
 tree_id=$(git rev-parse --verify ${GITHUB_SHA}^{tree})
 repo_url=$(git config --get remote.origin.url | sed 's/[email protected]:/https:\/\/github.com\//' | sed 's/.git$//')
 
@@ -34,10 +30,5 @@ jq --compact-output '.' <<EOF
     "timestamp": "$commit_timestamp",
     "tree_id": "$tree_id",
     "url": "$repo_url/commit/$commit_id",
-    "merge_commit": {
-        "id": "$commit_id",
-        "message": "$commit_title",
-        "timestamp": "$commit_timestamp"
-    }
 }
 EOF