Add support for not followed by await expression

grammar.js

@@ -562,12 +562,7 @@ module.exports = grammar({
     // -                                  Expressions                              -
     // -----------------------------------------------------------------------------
 
-    _expression: ($) =>
+    _expression: ($) => choice($._primary_expression, $.conditional_expression),
-      choice(
-        $._primary_expression,
-        $.conditional_expression,
-        $.await_expression,
-      ),
 
     _primary_expression: ($) =>
       choice(
@@ -590,6 +585,7 @@ module.exports = grammar({
         $.array,
         $.dictionary,
         $.parenthesized_expression,
+        $.await_expression,
       ),
 
     _rhs_expression: ($) => choice($._expression, $.lambda),

test/corpus/source.txt

@@ -245,6 +245,20 @@ func x():
 			(variable_statement (name)
 				(await_expression (attribute (get_node) (identifier)))))))))
 
+=====================================
+Await Not Expression
+=====================================
+
+not await test()
+
+---
+
+(source
+  (expression_statement
+    (unary_operator
+      (await_expression
+        (call (identifier) (arguments))))))
+
 =====================================
 Breakpoint Statement
 =====================================