Auto format let-else block (#10214)

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rustfmt 1.6.0 has added support for formatting [let-else
statements](https://doc.rust-lang.org/rust-by-example/flow_control/let_else.html)

See https://github.com/rust-lang/rustfmt/blob/master/CHANGELOG.md#added

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crates/nu-parser/src/parser.rs

@@ -2822,7 +2822,7 @@ fn parse_collection_shape(
         while idx < tokens.len() {
             let TokenContents::Item = tokens[idx].contents else {
                 working_set.error(key_error(tokens[idx].span));
-                return mk_shape(vec![])
+                return mk_shape(vec![]);
             };
 
             let key_bytes = working_set.get_span_contents(tokens[idx].span).to_vec();
@@ -2831,7 +2831,9 @@ fn parse_collection_shape(
                 continue;
             }
 
-            let Some(key) = parse_value(working_set, tokens[idx].span, &SyntaxShape::String).as_string() else {
+            let Some(key) =
+                parse_value(working_set, tokens[idx].span, &SyntaxShape::String).as_string()
+            else {
                 working_set.error(key_error(tokens[idx].span));
                 return mk_shape(vec![]);
             };
@@ -4026,7 +4028,11 @@ fn parse_table_expression(working_set: &mut StateWorkingSet, span: Span) -> Expr
     }
 
     let head = {
-        let Expression { expr: Expr::List(vals), .. } = head else {
+        let Expression {
+            expr: Expr::List(vals),
+            ..
+        } = head
+        else {
             unreachable!("head must be a list by now")
         };
 
@@ -4058,7 +4064,8 @@ fn parse_table_expression(working_set: &mut StateWorkingSet, span: Span) -> Expr
                         expr: Expr::List(item),
                         span,
                         ..
-                    } = ls  else {
+                    } = ls
+                    else {
                         unreachable!("the item must be a list")
                     };