Enable clippy::needless_question_mark (#8759)

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

Release Notes:

- N/A

crates/workspace/src/workspace.rs

@@ -1243,11 +1243,10 @@ impl Workspace {
                 }
             }
 
-            Ok(this
-                .update(&mut cx, |this, cx| {
-                    this.save_all_internal(SaveIntent::Close, cx)
-                })?
-                .await?)
+            this.update(&mut cx, |this, cx| {
+                this.save_all_internal(SaveIntent::Close, cx)
+            })?
+            .await
         })
     }