Let the article deletion logic happen entirely in the backend

cmd/backend/articles_contributors.go

@@ -112,14 +112,3 @@ func (db *DB) UpdateArticleContributors(articleID int64, contributorIDs []int64)
 	}
 	return fmt.Errorf("error: %v unsuccessful retries for DB operation, aborting", TxMaxRetries)
 }
-
-func (db *DB) DeleteArticleContributors(articleID int64) error {
-	query := "DELETE FROM articles_contributors WHERE article_id = ?"
-
-	_, err := db.Exec(query, articleID)
-	if err != nil {
-		return fmt.Errorf("error deleting articles_contributors %v from DB: %v", articleID, err)
-	}
-
-	return nil
-}