Add `ActiveValue::set_if_not_equals()` #4240

Job	Run time
Clippy	1m 21s
Init	4s
Examples (examples/actix_example)	2m 34s
Rustfmt	20s
Examples (examples/axum_example)	2m 27s
Unit Test	3m 12s
Examples (examples/basic)	1m 21s
Examples (examples/graphql_example)	2m 42s
Examples (examples/jsonrpsee_example)	2m 39s
Examples (examples/loco_example)	3m 28s
Examples (examples/poem_example)	2m 22s
Examples (examples/proxy_gluesql_example)	1m 24s
Examples (examples/rocket_example)	3m 6s
Examples (examples/rocket_okapi_example)	3m 11s
Examples (examples/salvo_example)	2m 47s
Examples (examples/seaography_example)	2m 30s
Examples (examples/tonic_example)	2m 34s
Compile PostgreSQL (tokio, native-tls)	2m 57s
Compile MySQL (actix, native-tls)	2m 50s
CLI	0s
Compile PostgreSQL (tokio, rustls)	3m 0s
Compile MySQL (actix, rustls)	2m 57s
Compile SQLite (async-std, native-tls)	2m 54s
Compile SQLite (async-std, rustls)	3m 13s
Issues Matrix	0s
Issues	0s
MariaDB (10.6, actix, native-tls)	2m 17s
MySQL (8, actix, native-tls)	3m 22s
MySQL (5.7, actix, native-tls)	3m 45s
Postgres (14.4, tokio, native-tls)	7m 7s
SQLite (async-std, native-tls)	4m 25s
SQLite (async-std, rustls)	4m 31s
	1h 21m 20s

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