Fix clippy warnings #2159

Job	Run time
Build `sea-query`	58s
Clippy	1m 20s
Build `sea-query-postgres`	39s
Build `sea-query-binder` (async-std, rustls)	1m 50s
Build `sea-query-rusqlite`	36s
Rustfmt	12s
Derive Tests	41s
Unit Test	1m 38s
MariaDB (10.6, sqlx_mysql)	1m 14s
MySQL (8, sqlx_mysql)	1m 16s
Any	1m 4s
MySQL (5.7, sqlx_mysql)	1m 20s
PostgreSQL (14.4, postgres)	1m 2s
SQLite (rusqlite)	24s
PostgreSQL (14.4, sqlx_postgres)	1m 14s
SQLite (sqlx_sqlite)	55s
PostgreSQL (13.7, postgres)	51s
PostgreSQL (13.7, sqlx_postgres)	1m 9s
PostgreSQL (12.11, postgres)	46s
PostgreSQL (12.11, sqlx_postgres)	1m 14s
	20m 23s

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