Enable clippy::useless_format (#8758)

This PR enables the
[`clippy::useless_format`](https://rust-lang.github.io/rust-clippy/master/index.html#/useless_format)
rule and fixes the outstanding violations.

Release Notes:

- N/A

crates/collab/src/db/tests.rs

@@ -23,7 +23,7 @@ pub struct TestDb {
 
 impl TestDb {
     pub fn sqlite(background: BackgroundExecutor) -> Self {
-        let url = format!("sqlite::memory:");
+        let url = "sqlite::memory:";
         let runtime = tokio::runtime::Builder::new_current_thread()
             .enable_io()
             .enable_time()