Enable clippy::clone_on_copy (#8728)

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

Release Notes:

- N/A

crates/call/src/call.rs

@@ -302,7 +302,7 @@ impl ActiveCall {
             return Task::ready(Ok(()));
         }
 
-        let room_id = call.room_id.clone();
+        let room_id = call.room_id;
         let client = self.client.clone();
         let user_store = self.user_store.clone();
         let join = self