Format let-else with rustfmt nightly (#5461)

Support for `let…else` formatting was just merged to nightly
(rust-lang/rust#113225). Rerun `cargo fmt` with Rust nightly 2023-07-02
to pick this up. Followup to #939.

Signed-off-by: Anders Kaseorg <andersk@mit.edu>

crates/ruff_python_formatter/src/expression/expr_bool_op.rs

@@ -49,7 +49,7 @@ impl<'ast> FormatBinaryLike<'ast> for ExprBoolOp {
         let comments = f.context().comments().clone();
 
         let Some(first) = values.next() else {
-            return Ok(())
+            return Ok(());
         };
 
         write!(f, [group(&first.format())])?;