Enable clippy::useless_conversion (#8767)

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

Release Notes:

- N/A

crates/recent_projects/src/recent_projects.rs

@@ -536,7 +536,7 @@ mod tests {
             !cx.has_pending_prompt(),
             "Should have no pending prompt on dirty project before opening the new recent project"
         );
-        cx.dispatch_action((*workspace).into(), menu::Confirm);
+        cx.dispatch_action(*workspace, menu::Confirm);
         workspace
             .update(cx, |workspace, cx| {
                 assert!(