feat(merge-git-remote): use temporary refs to avoid conflicts during fetch

bin/merge-git-remote

@@ -42,10 +42,10 @@ merge-git-remote() {
             key=$(echo "$line" | awk '{print $1}')
             merge_ref=$(echo "$line" | awk '{print $2}')
             remote_name="${key##merge.$git_folder.}"
+            tmp_ref="refs/merge-tmp/${remote_name}-$(echo "$merge_ref" | tr '/' '-')"
 
             echo "Fetch ref $merge_ref from $remote_name"
-            git -C "$git_folder" fetch "$remote_name" "$merge_ref:$merge_ref"
-
+            git -C "$git_folder" fetch "$remote_name" "$merge_ref:$tmp_ref"
         done < <(git config -f .gitmodules --get-regexp "merge\.$git_folder\.")
 
         # Merge refs into merge branch