patch 8.2.2212: Vim9: lambda with => does not work at the script level

Problem:    Vim9: lambda with => does not work at the script level.
Solution:   Make it work.
diff --git a/src/testdir/test_vim9_assign.vim b/src/testdir/test_vim9_assign.vim
index d5e1b33..ea344fe 100644
--- a/src/testdir/test_vim9_assign.vim
+++ b/src/testdir/test_vim9_assign.vim
@@ -1027,11 +1027,11 @@
   # check if assign a lambda to a variable which type is func or any.
   var lines =<< trim END
       vim9script
-      var FuncRef = {->123}
+      var FuncRef = {-> 123}
       assert_equal(123, FuncRef())
-      var FuncRef_Func: func = {->123}
+      var FuncRef_Func: func = {-> 123}
       assert_equal(123, FuncRef_Func())
-      var FuncRef_Any: any = {->123}
+      var FuncRef_Any: any = {-> 123}
       assert_equal(123, FuncRef_Any())
   END
   CheckScriptSuccess(lines)