patch 8.2.1826: Vim9: cannot use a {} block at script level

Problem:    Vim9: cannot use a {} block at script level.
Solution:   Recognize a {} block.
diff --git a/src/ex_cmdidxs.h b/src/ex_cmdidxs.h
index 0f9eb39..2e59d2c 100644
--- a/src/ex_cmdidxs.h
+++ b/src/ex_cmdidxs.h
@@ -69,4 +69,4 @@
   /* z */ {  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0 }
 };
 
-static const int command_count = 571;
+static const int command_count = 573;