[3.10] bpo-34013: Generalize the invalid legacy statement error message (GH-27389). (GH-27391)

(cherry picked from commit 6948964ecf94e858448dd28eea634317226d2913)

Co-authored-by: Pablo Galindo Salgado <Pablogsal@gmail.com>
diff --git a/Lib/test/test_syntax.py b/Lib/test/test_syntax.py
index ad5656b..6e1531e 100644
--- a/Lib/test/test_syntax.py
+++ b/Lib/test/test_syntax.py
@@ -1305,7 +1305,7 @@ def test_expression_with_assignment(self):
         )
 
     def test_curly_brace_after_primary_raises_immediately(self):
-        self._check_error("f{", "invalid syntax", mode="single")
+        self._check_error("f{}", "invalid syntax", mode="single")
 
     def test_assign_call(self):
         self._check_error("f() = 1", "assign")