fix: address PR comments about field names and redundant rows.Close()

- Use sqlc.arg() to name unnest parameters in AddBookTags query, generating
  BookIds/TagIds instead of Column1/Column2
- Remove redundant rows.Close() calls in MySQL and SQLite generated files
  for GetBookTags, GetBooksByAuthor, and ListBooks functions

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: kalbasit

example/db/query.postgres.sql

@@ -58,7 +58,7 @@ VALUES ($1, $2);
 -- INSERT INTO book_tags ("book_id", "tag_id") VALUES (unnest($1::bigint[]), unnest($2::bigint[]))
 -- @bulk-for AddBookTag
 INSERT INTO book_tags ("book_id", "tag_id")
-VALUES (unnest($1::bigint[]), unnest($2::bigint[]));
+VALUES (unnest(sqlc.arg(book_ids)::bigint[]), unnest(sqlc.arg(tag_ids)::bigint[]));
 
 -- name: GetBookTags :many
 -- SELECT t."id", t."name", t."created_at", t."updated_at" FROM tags t INNER JOIN book_tags bt ON t.id = bt.tag_id WHERE bt.book_id = $1