Fix Rust beta compiler errors 1.78.0-beta.1 (#5439)

* remove redundant imports

* fix test

* contains key

* fmt

* Merge branch 'unstable' into fix-beta-compiler

watch/src/database/utils.rs

@@ -1,6 +1,5 @@
 #![allow(dead_code)]
 use crate::database::config::Config;
-use diesel::pg::PgConnection;
 use diesel::prelude::*;
 use diesel_migrations::{FileBasedMigrations, MigrationHarness};